Evicting a 'tenant' whos not suppose to be there

[Robert Mouser]

I have a SFH that was rented to an older couple for the last 2 years. Apparently at some point their daughter came to 'visit' and never left.

The daughter also brought a cat with her and the house is now infested with fleas.

The couple went into a nursing home in September. Their son (who is POA) came from out of town and paid rent for October and November. He is using this time to attempt to clean the place up...gather his parents belongings and he paid for an exterminator whos been there 3 times so far. He is making some attempt at giving me back the house in good condition.

But back to my main question. The daughter was in an argument with her brother the other day and apparently is refusing to leave.

He has also had the utilities shut off so shes there with no utilities I think. (not sure if theyre actually off yet) This is in Northern Ohio so its plenty cold.

She is not on the lease....never has been. She's not suppose to even be there.

Do I have to formally evict her?

It seems like I should just be able to call the Sheriff and have her removed.

If I have to evict her do I have a case to make the parents pay for the eviction?  Since they allowed her to move in against the lease.