Difficult family situation, regarding my recently deceased grandmother. [View all]

[Coventina]

I posted several months ago about my 99 year old grandmother passing away.

It fell to me to go through her jewelry...

The only item of *real* significance that she had was a locket she always wore. Inside of it were tiny photos of herself and her husband at the time of their marriage. It's probably not worth anything of significance monetarily, but anyone who knew her would recognize it as an integral part of "her."

I texted the family about it and asked if anyone wanted it and there were no responses via text (no bigee, as I said I was happy to keep it if no one else wanted it).

Later that day, my sister called me up and asked if her daughter could have it.

Some background info: Her daughter has disowned most of our family, and has been completely out of the picture since 2015.
Basically, she's mad at her mother (long story) and since her mother and I are super close, she's chosen to cut me out of her life as well.

I said, well, I'm not really in a good place with your daughter right now, and I don't even know why, aside from being collateral damage.

We continued to talk, but the conversation about what to do about the locket never got resolved.

I'm not inclined to give a cherished memento of my grandmother to a niece who refuses to have anything to do with me.

My sister acknowledges that, but her argument is that I have no living children, and her daughter is the one who is the rightful heir to a family heirloom like that. But, we don't even know if she actually wants it!

Am I being unreasonable?

on edit: typo