It sounds like you want to be in the band - then do it. Tough if she does not like it, tough if she is upset that you might run into each other.

You have to do things for you, and not think if I do or do not do this will she come back. What if she never comes back - then an oportunity missed.

Friendships forged in MLC do not last long anyway, she will move on, to other friends.