[name changed]
Hi, I would just like to check if I am being unreasonable to feel hurt by my sister's lack of interest in her niece (my DD).
My sister is 7y younger than me and growing up, I was more of a mother figure to her than a sibling. We are both in our thirties and married, both living in countries other than the one we grew up in. She has always been less emotionally engaged with our parents and has a history of calling me only when she needs something (usually an advice which she rarely follows). DH and I had a 6y long fight with infertility which finally ended in 2019 when we became parents to a wonderful baby girl. Both sets of grandparents are delighted for us, but what hurts me is my sister's almost complete lack of interest in her niece. If we speak on the phone and I share something about DD, my sister will immediately follow up with a story about her friend's baby. If I send her a photo of DD, she'll respond by sending me a photo of that child. The kid is wonderful (And so is the friend) and normally I wouldn't mind but it is quite obvious that it has now been literally every time I even mention DD. For a while I thought she may be doing that because that's her closest other reference to motherhood and she wants to contribute to the conversation - but now I am not so sure. She never asks about DD or if she does, it is in a way that suggests she's doing it because she feels she should, not because she really wants to know.
I love my sister very very much and would hate to see our relationship hurt over this so if I am being unreasonable I'd like to know so that I can deal with it on my own.