AITA for crying when I heard my stepdaughter say she doesn't love me and wishes her dad and I hadn't married?

I (44f) married my husband 8 years ago. His first wife died when his daughter was 5. She was 9 when we met and 11 when we got married. We have what I always considered a pretty good relationship and I love her and she's a good kid and now young adult. I could never have kids of my own and I accepted that. I never expected, suggested or implied I wanted to be her mom. I was happy to be a part of her life and some part of her family. I did think we loved each other. But I learned this was one sided at Christmas.

My husband's extended family planned a few days away after Christmas to spend as a family. We rented a cabin and everyone was under one roof for a few nights. I fell ill halfway through and stayed in bed most of the latter part of the trip. One of those days I woke up from a nap and could hear my stepdaughter and SIL talking and I didn't hear all of it but I did hear her tell her aunt she doesn't love me and really only tolerates that her dad married me because he's happy but she wishes he hadn't married me, or anyone.

I turned on the TV to drown out the sound but then I started crying. It made me sad and I won't lie and say it didn't or that it didn't bother me at all. But I was never going to bring it up. Then SIL checked on me after a while and found me crying. She realized I must have heard some of it and told me I should never have listened and that crying wouldn't solve anything. Then she told me not to start any trouble based on what I heard. I said I wasn't going to but I just needed to let it out.

I didn't bring it up again and I was happy to let it go. But my SIL brought it up again and she told me I could feel a certain way but at my age and given my stepdaughter's loss I shouldn't have made it about me by crying. She told me she hoped I wasn't planning to get my husband to go after my stepdaughter. I told her I never said a word to my husband. I said I wasn't trying to make it about me.

She claims that couldn't be true when I cried and I should think about that so it never comes out around others.

AITA?