I agree with divine1966. I don't feel that I have complete information about the history to understand her reasoning...and there may not even be one personally against you. If it seems completely out of the blue, it is possible that:

a). Your group leader was harassed by someone else and decided to set new boundaries for everyone.

b). Another group leader was harassed in the church and the church has set a new policy for boundaries.

I mean, these are only speculations...sometimes you think someone is mad at you but it has nothing to do with you and has more to do with what's going on in her personal life.

If you feel that her behavior was something personal against you (like she's very friendly with everyone else), then try to think back at the times she was giving you gentle clues about boundaries. This may be the first time that she explicitly set boundaries with you.

But whatever the reason may be, it is not worth your time and energy trying to be close with someone who doesn't feel the same way about you. Just pursue friendships that are mutual, where people appreciate and honor your good traits.