Is it normal my friend is strange about my boyfriend?

When me and my friends were around 14 to about 16, so it started about six years ago, my friends used to be friends with a guy that lived near them. I don't live near my friends so only knew this guy on basic terms. Well all of them used to have this teenage crush on his older brother.
Anyway, six years on which brings us to a few months ago, I happen to meet this older brother. Not long after I realised who he was and asked a friend is she knew him. She acted really urgent and said why are you asking me this?! I then revealed we have started dating and she just said, yeah I know him. After this I have mentioned him to her. First time she acted weird and uninterested/bored. Second time she completely ignored me, which she never does.
I thought it was a silly teenage crush. It happened years ago. He is a very handsome man but I thought it all let go. Do you think she still likes him?
is it normal she is acting strange about him? She never is like this with any of my past boyfriends.