To tell child not to be in any photos without her sister

And they can want a good future relationship with there biological grandchild all they want.. They probably won’t get one if she grows up watching her sister excluded and her mum upset.

She can want it as much as she likes - it’s not something she’s going to get, and it would be foolish to expect them to provide it (unless of course she enjoys disappointment) when they’ve clearly and repeatedly communicated that they’re not going to.

If I were you op I’d tell them how you feel, if they don’t change stop letting them be around your older child. I doubt your younger daughter will want to spend Christmas/birthdays/Easters at there house away from her mum and sister so it will be them who misses out anyway.

All she wants is for her daughter to not have it rubbed in her face.. All of this because they can’t be kind people and put her in a photo frame with her sister.

Sorry OP, but unfortunately this is often the sad reality for children whose mothers choose to have more children with a man.

They cannot force his family to behave like she is their grandchild if they do not feel it.

I feel awful for children like your daughter as they are othered by their step fathers family and it can really sting.

But ultimately it is their mothers choices to have a second family and another child that puts them in this situation.

You can expect them to be kind to her, but for many people, sadly that is as far as they are prepared to go, and they will not see your child as their grandchild.

I agree and my half brother was always treated the same as other grandchildren as the rest of us. But people aren’t the same

They’re not her grandparents/cousins/whatever and they’ve been very clear they’re not going to act like they are. You can have the whole of mumsnet telling you they’re being unreasonable and pontificating about what they ‘should’ do, but so what? Are they going to care? No. Are they going to change? No. Your reality is what it is, and you would be wise to come to terms with it.

Your children have completely different paternal families, and as such don’t share all the same relationships. That your eldest doesn’t have a good relationship with her paternal family is not the fault of your in laws, and it isn’t something they need to step in and compensate for.

I have so many different opinions on this post but it should come as a warning to anyone who is a single parent to a child where the child’s father/extended family are absent.. Find out your new partner’s opinions on these matters before having another child. It sounds so damaging to your first and excluded daughter. I personally would not treat any step children in my family differently but not everyone feels this way and you can’t force it. I have been in your shoes op with my own son and I had to just tell him the truth in the end.. Not everyone has hearts big enough and that’s there problem, I refuse to let it be rubbed in his face though so my husband visits his family alone.
Another thing for anyone with step grandchildren reading this thread to think about is this.. I grew up with four friends as a child, there were 2 younger girls and two older. There parents married and they became step siblings. They saw themselves as siblings and all got along well. I spent a lot of time around them, holidays and Christmas so got to know the grandparents of the younger two, like ops child the older girls had no contact with there mum or her family. They grew up calling there step grandparents Nan and grandad. 35 years later there family has gone to shit. The grandparents died and only left inheritance to the bio grandchildren. This came as a surprise and caused a huge shit storm. This was around 5 years ago now and sadly they have not been able to get over it, so the grandparents are dead and buried but there bio grandchildren have lost two siblings, and cousins who will never know each other. Christmas/birthdays/weddings all screwed. Not to mention the resentment that will inevitably grow between their own parents, worth asking yourself if it’s worth it.

I was using it as an example of the myriad of things I didn’t consider such as how hurt I am about my children having different life experiences.

This is the issue though. You are making it about your feelings and your sadness that one of your children does not have the neat nuclear family set up that the other has. It's not other people's fault, or job to become the relatives your DD doesn't see.

Your 5 year old should be in the photo with her cousins.

When you choose to have children with two different people, these are the realities you are faced with. Your 5 year old shouldn’t be distanced from her her paternal family eg excluded from photos to make a point or miss out on events / days out / love from family just to make a point. You’re expecting her to handle your feelings by missing these sorts of things.

Your grandparents were obviously decent people not fixated on blood relatives

I think you're being unfair. Of course the grandparents might want pictures with their grandchild. You are being ridiculous.

This. Your husband has chosen to accept your daughter as a stepchild, his extended family don't have to. They aren't related to her by blood & for a lot of people, extended family relationships are primarily that.

@SpanishFork I don’t meant to be difficult but could it be that you’re really very conscious your eldest isn’t your husband and feeling extra sensitive. If they really are excluding and it’s not a manifestation of your complex about it (sorry to sound blunt) then that’s bloody awful and you need to pull them all up. Don’t let either children be aware of this or ask them to manage it.

I had an incredibly close bond with my grandparents but I would have been horrified had they behaved in a less loving way to my step "cousins". Fortunately they weren't hideous people.

But they’re not splitting upas far as we know

Also, more importantly probably, the OP has already said her eldest does not see her biological dad, and her DH sees her as his daughter. So if they split up, she will still be the Grandparents sons daughter!

I doubt that very much. If they have split up, it's highly likely that the OP would never see these grandparents and the younger daughter would see them when she is with her dad. The older daughter probably wouldn't go to the step dad's house.

You don’t know that he won’t t want to see her

This must be so so hard for you. I only have one child but DH has an elder child from a previous marriage. My parents are at pains to treat their only biological grandchild (my son) exactly the same as his sister (my step daughter). They get equal gifts and savings contributions etc. They are of the opinion that there is more to family than biology and I couldn’t be prouder of them for that.

however, you shouldn’t put your small child in the middle of things and you should take financial precautions to protect your elder child in the future.

Well that would depend on the breakup surely.

Always easy to promise you wouldn’t screw the other person other or cut contact from their step and yet it happens or the ex step parent gets a new partner and doesn’t want step anywhere near anymore.

She won’t though. He’s not her dad even if he acts like he is , she’s not their grandchild.

Your child is far too young to be expected to handle this. Rather unfair of you to dump this on a very young child. You deal with it as an adult, not passive aggressively through your daughter, using her as a pawn. Have the conversation like a grown up if it bothers you this much. Don't involve an innocent child.

She’s not their grandchild, it would be lovely if they treated her as if she was but if you divorce DH would they ever see her again? Do your ex partners parents treat your 5 year old like their grandchild?
Any rudeness etc. I’d not tolerate though.

You're not unreasonable to want your eldest not to feel like she has to stand in the corner and not be allowed to join in for photos but I did vote YABU for your question of involving your 5yr old in the solution.
I'd speak to the in-laws and say it makes your eldest feel like shit and can they at least do some photos with her in and try not to be so bloody obvious about getting photos without her in, she's only a child and it's only a photo ffs its not like you're asking for much

Also, more importantly probably, the OP has already said her eldest does not see her biological dad, and her DH sees her as his daughter. So if they split up, she will still be the Grandparents sons daughter!

Tbh OP, I would talk to your in laws about this and explain how it makes you and your oldest DD feel.
I would say something along the lines of 'myself and dd love you all dearly. DD is starting to notice that you don't send her a birthday present but you send one to her sister which she doesn't make a fuss about as she knows she isn't your grandchildren, but you both hope you care about her enough to send a small token so she isn't left out. Also her been asked to step out of family pictures really upsets her. An6 suggestions on how this can be handled going forward? ,

I hope you manage to resolve it