Renting a room to your kids 18 year old friend?

[Derek Tellier]

So posting in off topic as I really don't know how this fits in, just wondering if anyone out there has been in this situation. 
My daughter's friend turns 18 at the end of August, her grandmother has already said once she's 18 she has to leave. Today the grandmother "kicked her out". We're letting her stay here for a couple of days and going to follow up on the legalities of her staying till she's 18 tomorrow, I don't want to put myself in any bind there. 
But at the end of Aug she's 18 and free to leave anyway. I've got plenty of room in the house and already had longer term plans to rent out some rooms in the near future anyway. 
I'm leaning towards offering to let her stay once she's 18. She'd have her own room and share a bathroom with my daughter. She still has this whole year of high school left so trying to figure out if I should charge her rent while she's a HS student or chalk these next few months up to charity. She has a job but won't be getting her license till after she's 18 and of course will still then need to buy a car. 
I want to help her out but don't want to turn my home into a halfway house either. She'll need a place anyway so maybe I just charge something small like $100/month? Would you do a lease on something like this? 

Anyone been there done that or have any advice on it? 
Thanks

[Colleen F.]

I am not going to take this not as a financial question because she doesn't really cut it now financially.  Would you accept her if you are looking for a tenant (behavior wise) because it ends there if you wouldn't , she has to find someplace else.  If you would accept her in your home I would definitely create a financial relationship at least in my state.  If you need to get someone out who is a tenant vs a non-paying friend there is a different process. My brother had this happen to him and with the non-paying family members of his girlfriend it was tough. Maybe you want a month to month lease/ agreement but I doubt you can do one until she is 18 although not sure she would know that.  I would include rules of house etc. and you could change cost as he is done with school.   Consider is this room and Board or how would that work? I assume future room renters would not include board.   I have had friends of my son stay but their character and lifestyle was such that it could only be short-term.  It is a tough decision.