We've seen it before, as in Rushee #2's case, that legacies sometimes get cut very heavily from other houses, assuming they'll go to their legacy chapter and not wanting to "waste" the spot on them. This could have been a posibility.
I'm glad your daughter is sticking with it!
I got cut from (what I thought was my) #1 right before pref, but (it's trite, I know, but it's true) I ended up where I belonged.
It doesn't feel great going home after the 3rd party, when 80% of the other girls have a 4th to go to, but you can still find your home!