How often do you see them/expect to see them? How involved are you in their lives? Do you have your own things going on eg hobbies, friends etc?
DM lives alone, a few hours from us (me DH AND 3DC). I find juggling family life with her expectations around frequency and length of visits difficult. She always wants us to stay for longer and visit more often. She lives alone, she's single and cites these as reasons for expecting more from me.
I like being at home, I don't enjoy staying at her house for more than a night or two. So we seem to always been in conflict.
There is obviously more detail I could go into but we have a complicated relationship so for the sake of brevity I'll not go into it here except to say my brother and I think she has traits of covert narcissism.