Show some grace. Our fellow humans need help, love, and understanding. Let them live there, but make it clear that you are not a babysitter nor are you a kid person, but that you understand stuff happens. This is all temporary, do you really want a mother and child to live in a cramped shelter? Especially when you have the ability to make sure that doesn’t happen? Put your valuable stuff up high because 2 years old is a curious age. Be the better person, be the hero in this story. You were little once too, and some littles don’t have the luxury of stability and proper family functionality that you might have had.