To have called time on my marriage. A family of two halves.

But if this is the op who posts frequently about this issue, agree.
shared dd is not allowed to do anything with her half sister from dad or her parental Gps without the ops dd being centred…:
the inheritance is a big thing, as op on that thread’s is insisting she gets exactly the same from non relations and has stated she will disinherit youngest dd to give her own dd more…

OP's previous thread on this issue - www.mumsnet.com/talk/am_i_being_unreasonable/5436923-step-daughter-versus-daughter-mumsnet-bingo

I agree.
OP and DH should come up with a figure they can afford and that's what they are willing to pay for extra curriculars for teh eldest daughter... ILs can pay for the other 2 girls. Once that value they can afford is used up, no more activities for any of the kids.

2 adults who should never have become parents. Either one of them.

2 adults who should never ever embarked on any kind of relationship together

Not paying for extracurricular activities for OP's eldest is not even close to treating her like a dirty secret. OP has said her MIL is polite and nice to her eldest.

MIL doesn't consider her a grandchild. OP is not her child. She's providing an experience for her grandchildren. She's not providing for OP's eldest. That's likely why she's bypassing OP's husband in the money gifts.

If she had passed out money to OP's husband, OP would be getting some of that as a marital asset. So MIL is doing the right thing if her goal is to keep her money in her bio family.

I appreciate this might not be financially possible, but I would see their contribution(s) as a 2/3 subsidy.

Let’s assume it is horse riding and the cost is £150 a month per girl. So 3 girls is £450 a month. Your ILs are stumping up £300
of the cost so it costs you £150 a month to take all three girls.

It isn’t the IL’s job to treat them all equally although in an ideal world they would. It’s up to you and your DH to find a way of dividing up outgoings to equalise the situation. It may be that you need to cut back on another extra curricular of DD3’s to pay for the extra horse riding. I think it’s fair. As long as they all end up with roughly equal opportunities it doesn’t matter if you never actually spend your own cash on DSD and DD3 and the ILs do it.

Not to stomp on OP any further but really what’s grim is that ultimately she was okay with entering a marriage knowing her first DD would always be treated as not being family. She’s her mother so ultimately this is on her shoulders and her shoulders only.

Oh this won’t be over
It will all be swept under the carpet and will drag on interminably.

Expect another depressing thread from the op within a week or so.

Not really. They don’t treat her a grandchild because she isn’t one, beck isn’t the same thing as considering her a dirty secret or a piece of shit.

Grandparents passing their assets to their grandchildren is increasingly common, at least partly because of blended families being increasingly common. They aren’t unusual in their approach.

Seems as though your in laws view your eldest dd as some kind of dirty secret piece of shit. They have loads of money but choose to leave her out. I suppose these are the consequences. The fact that they are withholding early inheritance money from your DH because he has a stepdaughter is just grim.

Yes, I agree.
OP and her DH need to have a discussion about how this is treated in their house.

In an ideal world (IMO) they would just decide how much they can afford, and pay for DD1 for that value of activities and let MIL pay for the other 2 and then just decline anything further for all children.

People really don’t have to be dicks. The last time my stepmum saw my DD, she hugged DD and said, “I’m so proud of you, and I’m so glad you’re mine.” My heart melted. ❤️

Yep. I think what OP simply wants is for MIL to fund her daughter too but that’s not going to happen.

I don’t know how would that work then, what the MIL is doing is not on, but trying to force the MIL to pay for both if she doesn’t want to is ridiculous.

He can say no... but the OP doesn't want to say no so it's not necessarily a DH problem either. The OP doesn't want the youngest to be told no.

True, but OP lives in the house with shared DD now, yet still has no control about how ILs treat shared DD, because DH says nothing and facilitates the visits/activities anyway.

She isn’t “rejecting her”. She’s just not her granddaughter. And she isn’t. If OP and her husband divorce do you really think she will have the same contact with her as she does her actual grandchildren?

It’s very normal for grandparents to only fund things for their grandparents. It’s not their fault that OP made a bad choice for her eldest daughter’s father.

This, if it is, not surprised, just surprised it’s taken this long!

If you're saving the money by having two paid for can you not pay for the third? My family are not like this, blood is irrelevant and everyone is treated the same but it's common for it not to be that way, the argument being your eldest has her dad's family too, so if she got the same input from your husband's parents she'd potentially have 3 sources of treats etc whereas the others have two.

You don’t have a MIL problem, it is a husband problem. I understand why you are splitting, it is unbearable to see your child discriminated against while the wet blanket husband just shrugs it off and allows this treatment to continue. I would lose any respect I had for him too. He cannot and should not ask his mother to pay for the eldest girl but he shouldn’t accept gifts that disadvantage one of the children.

He can say no, he is choosing not to. I’m not sure how it will work after divorce, or if you will end up making the situation worse for the 2 girls by splitting but, if you cannot see him as a team player anymore, so be it, your child will know you had her back.

I do expect, however, that once he sees that you are serious about leaving he may hopefully grow a spine.

She will find the reason. Unless you try to block her from any contact with DH's family. Which you can't, he will take you to court if you aren't amicable.

How old is your eldest?

She is basically rejecting her husband's stepdaughter and is demonstrating she in not part of a family. In a normal, not weird and fucked up family like this one, all kids are treated the same - no matter where they came from.

It sounds like that even if the OP or the OP and DH paid for the activity that the eldest DD wouldn't be welcomed . And if it is riding that aunt and niece share , it's unlikely that the DD would be included. What if they buy the DH daughters a pony each ? It just sounds impossible.
You can say that your shared DD can't attend either but that's another problem. And if you divorce you will have no choice where your DH will bring your shared DD .

Your DH can't force his family to accept and certainly not expect to pay for your DD . I guess what he was hoping was that you and DD wouldn't make a fuss. How old are these girls ? Do they get along or are they acutely aware of the biological to differences ?

So the DH family wouldn't leave any inheritance if he married a woman with children or is it just you ? I do understand why the family wouldn't consider them family and maybe not fund things like uni , cars, inheritance. But by then your DD would be older and at least comprehend the difference in treatment. What I think is incredibly unkind and downright cruel is to do this to a little child . Especially their GDD sister .

My mother cannot look me in the face she is so angry.
Who’s your mother angry with—you, DH, or MIL?

Did MIL create wedges in DH’s previous marriage too?

@GeorgeClarkefan

But you don't have the money for everyone!

Honestly you cannot force your ILs to pay for any child. But you can decline or say "maybe next term if we can put together money for DD1". Even if you seperated the situation would be the exact same except you wouldn't see your DH and you'd see your youngest less.

Either you & DH find the money for the eldest child, you decline MILs offer to pay for youngest, or you explain to the eldest that unfortunately that life isn't always fair unfortunately and her sisters will sometimes do things she can't.

What's the age gap between your two daughters?