Not actually posting this on AIBU as I'd mainly like input from people who are also step parents (if possible!)
I have a DSD who is almost 7 years old. I've been in her life since she was 3. She stays over every Saturday night and we do 50/50 during holidays. She is important to me and since the day I met her I have gone out of my way to make her feel cared for and special, and as a result we have a very good relationship. I have been proactive in making her feel like part of my wider family, too.
Me and her dad (DP) also have a 9 month old son. She's taken very well to having a half sibling, and unless she's hiding it EXTREMELY well there doesn't seem to be any jealousy issues or behavioural problems that have cropped up. She's the same old kid she always was. It's me who is different now.
I have less time, energy and patience for literally everyone. My son wakes up a LOT through the night, we are co-sleeping and also 'breastsleeping'. I'm coping fine with caring for both me and my son, but I have very little left for anyone or anything else. He's a very demanding, high needs baby. He's also extremely heavy and wants to be carried 80% of the time through the day. He requires every last shred of my energy. However I know that if I was sleeping more than a 2 hour stretch at night I'd be no way near as exhausted by him.
My partner works until 9pm on a Saturday, and I am the only driver at the moment. He was picking DSD up when he finished work and getting public transport/taxi home with her, which meant her mum had to wait in on a Saturday night for him to arrive, and then he and DSD were getting back to our home really late. It wasn't ideal for anyone. This meant DSD ended up rarely staying over, so I offered to start collecting DSD at 5pm and sorting her out/spending time with her until her dad got back from work around 9:30/10pm. I've done this for about 3 months. Initially it was great, but it's not working for me anymore. I'm knackered enough as it is through the day, and once DS goes to sleep at about 7:30pm, I am spent. I just want to be alone, I don't want to do any extra childcare. In reality, I don't want to have the two of them on my own at all. Although I do I give her as much quality time (baking, playing games, colouring) as possible when I do have her on my own, it isn't the same as before. I don't love it like I used to. And as time goes on, I just really do not want to do it on my own at all. I don't want her to feel this from me and it end up effecting our bond irreparably, though.
I am still very happy for her to be here when her dad is here, because obviously we can share all the child care tasks out and it's just so much easier and more fun for us all.
I feel guilt about this though and I know ultimately it will end up disrupting her staying over again if I don't pick her up on Saturdays. I know things will change for me once I am getting more sleep in the next year or so, though...
But am I being unreasonable to not want to look after my DSD on my own until then?