I have a squatter what do I do?

[Crystal Tooker]

I have a squatter at our mobile home rental. The tenant left prior to the lease ending. She notified us she was leaving before the lease was up but would be paying the full amount of rent due prior to leaving because she felt bad for leaving early two months. So we go to the house to get back possession and there is a woman in the house we ask her her name who she is. She says shes the mother of the tenant who left and wont be leaving because she has squatter rights. What do I do? What are squatter rights? Shes not on the lease.