Sounds terrible but I don't feel a connection to my niece and it's not her fault at all. She is a cute little girl.
Background is I don't like sil very much for various reasons. She's quite selfish and has not treated DB well imo. Today, I'm visiting my mum and when arrived, I see that niece has been dropped off by DB before he went to work. While sil is going to have a "day off" (she doesn't work and hasn't had a job for years). My DCs played with her well and we had a nice day overall. But I resented having to looking after someone else's child on my day off. DM was preparing lunch and dinner etc and I ended up having to change niece's nappies and entertained her when my ones slept. We popped out for a walk and as her buggy was too heavy/ difficult to steer for DM so I ended up pushing it, in the heat.
I think I do love my niece but I don't seem to care for her as much as my other niece (DH's sister's dd). I'm not making that much effort to interact with her. What's wrong with me!?