SUZ has the best advice
Don't any of you watch TV judge shows. This type of case (baring the foreclosure issue) is judged all of the time.
A verbal agreement is just that, a verbal agreement. So now, it comes down to one persons word against another.
In this case it's easy, the landlord can say that they had a verbal agreement for a month to month lease and that the rent was $1200 dollars per month. Then the landlord produces evidence (bank statements, copies of the cashed checks, receipts, etc.) to demonstrate, that sure enough your daughter has been paying him $1200 monthly for the last several months. Case closed. How can your daughter dispute that?
The foreclosure issue is not germane to this case as it has nothing to do with the month to month verbal agreement the landlord has with the daughter. How the landlord spends the money, is not part of the month to month lease agreement. All he has to do is give her thirty days notice, and she is out on the street anyway.
As for the foreclosure aspect, yep your daughter is screwed. If he is a total dirtbag (and it sounds as if he is) he will keep taking her rent and not pay the mortgage right up until foreclosure. Then the sheriff willcome and "help" her move into the street. He will also keep the deposit, until she sues him for it. Good luck collecting it.
If he is less of a dirtbag, he will keep collecting her rent right up until foreclosure. But he will give her thirty days notice to vacate prior to the bank taking over, just like required on a month to month lease. Then return the deposit (yea right). That way he is legally covered when dealing with his tenant.
It's a crappy deal. I believe that some states are looking at laws to protect renters from dirtbag situations like this, as it seems to be more and more common.