Don't worry, this will stay between us. I only have to share things if someone is in danger and that's not the case here.
Typically I want guardians to be over the age of 21 but this is one of those cases where I can make an exception. It wouldn't be fair to separate you two.
What I would do is grant you guardianship but I wouldn't just walk away after. I'd keep checking in to make sure everything is going well. I won't take her away from you if it isn't, only help you get a place where it is. Does that make sense?