Tell your friend not to do do so unless required. If there was any genuine reason behind this, then ask her to share and ask the team members to forgive her once( if there was any genuine reason ). If not, then ask her to tell whether she is interested or not. If yes then tell her to come on rehearsals sincerely and if not then ask her to leave. If she repeats the same thing again and again then she is not required as it will only affect your practice as every single participant counts.