ok so just my two cents but this actually happened to me during my recruitment as well as a few other girls. I was in band and some other girls were cheerleaders; and we had an away football game on pref night. Therefore I (and about the other 4 girls) had to miss all of pref parties, we go to 2. The five of us all recieved bid on bid day, but of course this all depends on the campus and your daughter. My gamma chi (like a rho chi) had told me I could write letters to the groups I could possibly recieve invites to; so I wrote three letters to the three houses I had visited on skit night, even though only two letters would be needed as I could only get asked back to two houses.I also slipped the suggestion twnkle said in, I'm in band....wont be at pref.... and told the girls that talked to me that third night that I really could see myself here the day before pref (this according to my gamma chi was risky, but she mentioned i could do it but it may back fire). Thankfully all did work out and I am writing this from the sorority house now.
Anyway this is just what I did, however it definately depends on the campus, and all you can tell your daughter is to talk to her rho chi...she will most definately have the best advice for her.