Difficult step daughter and husband

I have been with my husband for 12 years since his eldest daughter was 12.

I have always found her to be difficult. Her parents were warring and her Mum made life very difficult for my partner despite him being a good Dad.

We had his daughter and his 3 other children around 40% of the time and it was hard work! I did all the normal day to day stuff for them all, washing their clothes, sewing name tags in school uniform, doing the school runs, cooking and shopping etc etc. We bought them all cars and paid for driving lessons, took them out ourselves in the car, took them on holiday, decorated their rooms how they wanted etc etc. We never had a child of our own and we both worked full time too, I have 1 child now grown up. One daughter moved in with us full time and barely saw her Mum. I think we did our best with all of them in very difficult circumstances. The two that lived with us full time are doing really well in adult life with relationships and careers etc.

Eldest daughter was always sullen and miserable whatever we did. I expected her to stop contact at some point but she never did. She came 40% of the time until she moved in with her now husband at the age of 19. When she was with us, she would just tell us how much better life was with Mum, even though it was clear Mum did very little for her or her siblings.

She has since got married and had a child of her own - we have financed a lot of this. Paid for the wedding and the deposit on their house and money for cars.

She lives about an hour away from us. She wants to come to our house every weekend and stay from Friday afternoon until Monday morning with her husband and baby.

My husband and I both work 6 and a half days a week, so only get a half day and the evenings together. We also still have 2 young adults at home. We say "no" every weekend to her requests because we are simply not at home and I refuse to just let them use our home as a free B&B. They do stay with Mum who doesn't have a job but they have said they would "prefer to sit on our sofa as our house is nicer".

I honestly think they thought we would be falling over ourselves to have them over all weekend because they have a baby. The baby is lovely and we want to have a relationship with her and we do see them 1 or 2 times a month for a few hours each time as well as regular messages.

We both find them very difficult to communicate with. They seem to be jealous of everything we do and have.

I just feel whatever we do, it is not enough and I do think they just don't like us very much.

She has now announced she is "depressed" by phone call to her Dad. She hasn't actually phoned her Dad for years. We have both tried to talk to her about this but despite her talking about her "medication" constantly and leaving tablets on the coffee table, telling us how she can't drive because of her "medication", telling us how her husband has to take time off work in case her "medication" affects her etc etc, she says she "doesn't want to talk about it" when I ask her how she is feeling.

I've always known she is unhappy and she says she is going to have counselling. I don't think her husband helps as he seems to be just as bad with his disdain of us.

But you know, I realise that all this affects MY mental health massively and I don't sleep after seeing them and have anxiety attacks when I know I am going to see them. Something I have not suffered from in the past despite a few pretty traumatic life events.

I am on a merry go round of trying my absolute best, getting kicked in the teeth, feeling guilty for getting it wrong and then trying some more.