Concern about roommate policies...

[Samantha Lotti]

My father recently moved in a roommate to his condo. He is currently purchasing it. When he passes, it will go to me. So my concern here is, should I have him take a legal route to guarantee that the lady understands she must move when he does pass?  I'm not trying to sound cruel, but I don't want any problems or her to become a squatter. 

Any advise or input is greatly appreciated!