my mother made a verbal agreement with some one and now that some one broke it and wants their money back. does my mother owe any thing?

Your mother's problem is both legal and personal.  Doing business with a relative is risky because, if things don't go well, family relations can be fractured or destroyed.  It is often hard to stand your ground on legal issues when doing so drives wedges between yourself and a relative.  But here is how I see it: Your Mom owns the duplex and she made a verbal agreement with her sister for the two of them to finance the purchase, live on the premises, and later (upon sale) they would split the net proceeds.  It is almost certain that under your state's law, a verbal contract like this would be unenforceable.  But if the sister had stayed put and kept her end of the bargain, I believe your Mom would also -- and everyone would be happy. I will assume that your Mom has paid half the mortgage payments for the past 13 years and so has her sister.  But now, the sister wants to pull out of the deal and get her money back.  If she gets her money  back, she will have lived there rent free for 13 years.  That isn't fair to your Mom who, in such a case, would be essentially required to pay "rent" on both units for those 13 years.    By moving out, she will be leaving your Mom to finish paying the house off by herself - again, not something your Mom bargained for.  It will be necessary for your Mom to rent the other unit to someone else so as to earn sufficient income to make the mortgage payments.  By moving out, the sister will be voluntarily surrendering her prospects of receiving some kind of pay-back in the future by a sale of the property  -- and she will remain liable on the note she signed with your Mom.  If your Mom can't make the payments and the house is foreclosed on, both of them would remain liable to the bank on any deficiency after the foreclosure.       From a purely legal standpoint, your Mom should hang tough but, by doing so, she may damage the relationship with her sister.  She may feel a lot of pressure to bend some. 

I believe that your Aunt would not be able to get the money back from your mother. In fact, if she is on the deed and the loan she is responsible to continue paying for the house even after she moves out. It is best to get an attorney to help you with this matter.   Walter Jennings, Esq.