She was down on her luck and needed a place to stay for 6 m. Its been 5 years now

First have you just asked them to leave ?

Give them a written notice to move out, and if they don't, you file in court for a official eviction.

It doesn't matter who she is. She is a resident in your home and that conveys on her tenant status. Therefore she needs to be evicted according to your local laws. Generally you give her a written notice to vacate within 30 days. If she hasn't, then you go to your local court and file for an evictions order.