Skipping any comment on your daughter's immaturity, I would suggest that you offer the landlord a medium-sized sum of money, along with written notice that your daughter is not going to move in. (If she can't write the letter herself, she's not competent to rent and take care of the obligations of an apartment).
A small claims judge is not likely to let the landlord keep much of the money, but you had better get proof that she changed her mind after 10 minutes and notified the landlord at that time. The theory here is that the landlord won't really have lost anything. But the judge will also probably feel strongly that your daughter deserves some kind of a ding for her behavior. Thats why she should make an offer first.
