Real estate land contract
My sister-n-law and i agreed to enter a land contract to take of over defaulted property when she left town; we turned the unit, caught up note, took care of violations and assumed responsibility; she renigged on signing the contract, held it for 6 months then said we breached and she was canceling our agreement. we acted in good faith and invested money on turning and maintaining unit, now we found out she was actually in process of secretly selling property, we have no signed agreement, as she failed to sign and return contract. what can we do to keep her from selling and not paying us what we put out in expenses and mortgage payments, and we have a renter in the house under a lease to us, not her.