I know that once my FI and I are married, his nieces will be my nieces too.
But I feel bad that I have a hard time calling them my nieces. We just recently got a picture of his brother and sister-in-law's new baby girl and I shared it on my Facebook (with the parents permission) and put the description as X's new niece instead of our new niece.
I had a few people ask my why I didn't say it was our niece.
I wonder if his nieces living at least 6 hours away (and seeing them maybe once a year) has anything to do with it. Some live almost a full day's drive away.
Does this make me horrible? Is it something I will get used to in time or that maybe I will feel different about / come more easily / naturally to me after the wedding? Did anyone else go through this?
Re: Does this make me horrible?
Don't force it or let it be forced on you. And if being called Aunt Hlvonb feels too weird but you and they want to acknowledge your new relationship status, you could always come up with a different, special moniker.
I may ask my brother & SIL to teach my nephew to call me Aunt Blergbot.
Also, he doesn't call DH Uncle DH, and he doesn't call me Aunt HisGirl.
My nephew, OTOH, calls me by an ethnic nickname for aunt and calls DH 'Uncle DH.'
I know my nephew thinks of DH as an uncle, but he's also only ever known DH as my SO. He's too young to remember my SO before DH, and DH has now been in my life for two of the three years my nephew has been alive.
We're getting a new nephew in September, and my current nephew has already announced, 'No share Auntie, Uncle with baby. Mine only!' Which is pretty cute.
I will say as an adult, when uncles of mine got married, I know their wives would think of us (my siblings and cousins) as our uncles' nieces and nephews and not their's together. My FH'a aunts and uncles accepted me as their niece but not most of the other cousins' SO.