Father is dead and rent free girl won't leave I live there too

It was your father who is dead and who owned the house?

How did this girl manage to take up residence in the house?

Has a probate case been filed?

Your question would be (I assume) how to get her out of there? That would be for the personal representative to worry about.

When the owner passed away the house became part of his estate. The executor of the estate has to begin the eviction process to get rid of the person who is living there, even though she doesn't pay any rent.