*The DH’s daughter isn’t obliged to fall in line and consider OP’s daughter to be her sister because OP would like her to.
who says they don’t consider her family? They don’t consider her to be close family, or the DH’s daughter (and neither does the DH, by the sounds of it), which isn’t the same thing as not considering her to be family. Their blood relation is a bridesmaid, I imagine they want her to be happy and comfortable on the day, with her own father and family members.
The DH doesn’t have a problem with this, so I doubt it will stop him interacting with family members he’s clearly close to*
By the sounds of it the stepdad never lived with his dd and had little relationship with her mother.
Whilst his life has moved on I think the dd didn’t want her father to have anyone else and equally I wonder if her mother is allowed to have any sort of relationship with anyone else. Hence why the ex is so pissed off that her dd won’t stay at her fathers house with his new wife and child
I think at 5 years old there should have been a gradual introduction to the new family set up with a short time spent with the new step mum and step sister and longer time with dad on his own to start with and gradually longer and longer spells with the family and some time alone with her father.
I think this 5 year old put her foot down and instead of the adults looking at the long term outcome they handed the power to a 5 year old who I think probably wants mummy and daddy to get back together and can’t get her mind round that they were never a committed couple in the first place.
I think you will find that the dd told the cousin that she didn’t want Tino’s dd at the wedding.
I think that long term they have set up this child for an incredibly hard life. As she gets older there comes a time where she is going to have to spend time with people she doesn’t know or is she only going to live and work with her primary school friends forever more.
i am sure the father in this won’t stop going to family events but from now on he will be on his own.
Seeing a similar scenario play out, the family events the father went to got less and less as his wife and step children wouldn’t go to these events as it had been made clear they weren’t seen as family
Maybe imagine the scenario that the dh won’t be invited to his step daughters wedding despite being married to her mother as its blood family only.