Somehow I missed this thread.
Blutang & Measi pretty much have this covered...it will most likely depend on the chapter.
My chapter never received any letters of recommendation, so they might not know what to do w/ it if they did receive one!
Definitely make sure she gets her grades up. We told a few prospectives to come back when they had a better grasp on their academic situation.
One thing that might help her is to volunteer w/ the band...such as if the school hosts an honor band, she should volunteer to be an usher, runner, etc. during the event. If they see her desire to serve the band program, that would probably help.