MIL not putting in effort and then complaining she feels “left out”.

Is she maybe put off from visiting because she thinks your mother will be there? I can see this being the reason if you all come as a bundle and she has to compete.

I wouldn't have been able to do that drive when I was the GM's age.

Not everyone can

It's very insensitive of you to thank your mother on social media. Akin to offering condolances over social media.
People can read all sorts of things into why they are not thanked for things by you.
It seems quite attention seeking; almost making a point of announcing to all that your MIL doesn't help to the same extent.

No-one's efforts and contributions are ever exactly the same but family members are equally loved and valued.
That is the unspoken belief that has unsettled MIL. She now feels like she is in a competition.
Her son needs to increase his communication. Your DH should be taking his children over to see his mother every fortnight so that the children are comfortable with MIL.

It is unusual for a Grandmother to be as involved as your mother is. You are lucky to have her help but it is okay to not be like your mother.

And for the record, before we moved to be closer to my parents, my parents lived 1.5 hours away and were still massively helpful and involved, including helping with childcare and giving us a break when need be. That was very possible without anyone needing to move.

Why hasn't your husband spoken to his father about not knowing his paternal grandparents?

But that's true, isn't it?

I wouldn't cope with your mother's level of involvement (as a GM) but if it suits the both of you (and your DH is ok with it) then crack on

I understand your MiL's reluctance to drive and being the distance away she is will also have an impact. Is her husband still alive? Can they come together?

And I also wouldn't be facetiming the children - I really don't do it (or Zoom or Teams or anything else involving video) so maybe accept her differences

You’re the one who seems to equate distance as a necessity for a relationship. I was responding to the point you made. At no point did I say a grandparent needs to be move so not sure why you’re fixating on that.

The mindset of not wanting to unpaid childcare sets the boundaries of how the the relationship will be, according to grandparents. Deciding that they will only help in emergencies, whatever the distance, shows that the grandparent expects to be hands off and not very involved. That is their prerogative but the consequence to that the relationship will be very different to one where the grandparents are involved.

Did you even bother to read the OP's posts?

It might be nice to break the pattern and go visit your grandmother?
You might find you really like her?

Horses for courses

I have done and still do quite a lot with and for my DGC

I would be aghast if anything about it was posted on SM

Sounds like your SIL is a bit of a snake. Why did she feel the need to shit stir? She knows her DM isn't on Instagram.

As for your MIL, I reckon if she tried to be as full on as your DM you would find her a bit of a pain in the back side. Most people would find that level of contact from anyone to be stifling.

That being said she sounds a bit shit, I do find people who say 'I've raised my children' were usually mediocre parents (who relied on GP help themselves!). Why does she expect you to drive your DCs over on the same roads she is afraid of? As for not replying to messages my MIL used to reply to DH when I was the one who messaged her, it makes you feel like you don't exist doesn't it? If she can't acknowledge you as the mother of her GCs in a simple message or even bother to write any reply at all, why would she expect you to write a gushing post about her?

She may not have the confidence /social skills to put herself forward.
She may be waiting to be asked/included.
Possibly you may be unintentionally be making her feel excluded. The Instagram post does seem out of place. What your Mum does for you and DGC is private, no one else's concern. This makes me feel your MIL may have been made to feel an outsider. TBH posting on MN seems to be another way of having a go at her, when she can't give her side of things.
I could be wrong but I feel something has made her like this.

My in-laws are like this. My parents and the in-laws both live 10 mins away. My parents have always been fully involved, see at least once a week, text all the time. They know everything about my kids and what they are like as people . Their likes and dislikes (teenagers now)
My in-laws are very nice people and very kind. But they have never built a relationship with the kids. We would always go round and they would just sit and have adult conversations, ignore the kids, didn't ask them questions etc. Whereas at my mums house they had as many toys as at home. My mum would play with them all the time.
In laws would go weeks if not months without ringing. I used to do it just to keep contact but I got so annoyed I told husband we would stop and see what happens. It went on for 6 months.
At Xmas they buy them gifts that they are not interested in or clothes they dont like as they dont know them. They dont even know what schools they go to and they forget their ages.
I used to get extremely upset about it. Then my SIL had a child and mil is exactly the same with them, never sees them. So then I knew it wasnt personal.
My kids are very happy to have such involved grandparents and they never even mention the other ones.
My own grandparents were the same. I had one who I saw all the time , one I never had a relationship with . That one is still alive, nearly 100, I haven't seen her for years

You can do what you like. I’m a similar age, working in a professional role but would want to be hands on with any grandchildren. I’d reduce my working hours to help out if it would be helpful & could fit in around my other commitments (lucky to have the option, but just where my personal priorities lie).

If I rarely saw them and the other grandparents saw them all the time I could hardly sulk if the other grandparents were more involved and had a stronger relationship.

I find women who discourage their mils usually have good reason and its usually because they over step and make everything about themselves... very similar to getting upset over a post your dil made for her own mother which she doesn't need permission for nor does she need to justify this to an mil who clearly saw the post and recognised that it highlighted what a lazy grandmother she is in comparison. Its her own hang up and nothing to do with the op. That aside there is nothing to suggest op has done this so im not sure what your point is.

😀
Is this ‘tongue in cheek’?

That can't be a genuine view of your children’s grandparent and a part of your family.

Now, I appreciate I probably shouldn’t have made the instagram post (maybe

she is your mum. You can make as many appreciative instagram posts about her as you want. One an hour all year if you like.

No. @Conversationalcheddar isn't harsh. The MIL has clearly made no effort and has also made it clear that she doesn't wish to make effort but yet expects the young family to make the effort with her.
@Conversationalcheddar your DH has two options re her message. One would be to not reply, simply ignore the outburst. The other would be to try to open up a conversation about how the two of you are surprised/hurt that she hasn't made more effort to see her son and grandchildren.

excactly

sounds like you prefer your own mum anyway

How often do you all drive over to see MIL so she can spend time with her grandchildren? Given your DM spends so much time with you, I would imagine you won’t be playing catch up on chores at the weekend as much as most families without your level of support so the whole family could see MIL when DH isn’t working. Do you work? You don’t mention the grandfathers, where are they in this set up?

Your dh should reply and tell her to stop being so ridiculous. If she wants credit or thanks then she should try actually helping sometime

That isn’t consistent with what you said.

You equated someone saying they could not be the unpaid childcare with someone saying they don’t want a close relationship with their DGC.

If a DC living an hour away told me to make sure my new car took their childseats I would also wonder what they would expect (although I would just ask). Asking if I want their seat specs in case its every useful is a very different question. A lot of this is about the communication and mismatched expectations.

Expecting grandparents to move house to help with children is unreasonable - we all have other children/family/jobs to consider. Presumably the OP is an only child. Its also easy to underestimate the barrier to a reserved person of having to arrange visits knowing there is a grandma in chief in residence most of the time. Usually both sides need to accommodate the other a bit where cultures conflict.

I note also there is rarely criticism of the FiLs for not downing tools and moving ten minutes away to be free childcare in these threads.

She sounds very self centred although also the post has unearthed her feelings of resentment and jealousy (which were already there) so in a way this a good opportunity for this to be tackled head on.
Your DH need to respond but should think carefully about the words perhaps using this to ask what MIL wants to happen and do differently, perhaps playback her own words about her being done with raising her own children and not wanting to raise yours ie what relationship would she like? This might be better as a conversation.
You have to put the ball back in her court about what needs to be different.

Lovely people don't ignore the existence of grandchildren because 'they don't like' their son's partner.

Lovely people don't rely on grandparent childcare themselves when raising their children, but aggressively spout 'I've raised mine' when they haven't ever been asked to babysit/watch their grandchildren.

Lovely people don't moan they're not being 'thanked' on social media when they haven't lifted a finger to maintain a relationship or have done anything to be thanked for.

Lovely people don't say they can't possibly visit their own son and grandchildren because 'they don't like driving' when they regularly drive the same distance to see other family. Which she does. Regularly.

Lovely people don't want other people, here their counterpart grandparent, OP's mum, to do LESS to make themselves feel better about not doing anything at all. Which is what's happening here.

Don’t play into it op or try to please her. Remember she’s just your dh mother, not someone who you need to win their approval. She doesn’t want to be involved, so she doesn’t get any recognition. Simple as that.