She shouldn’t have to share her bed with someone who is mean to her. 

What do you do when you have a guest stay at your house overnight when you don’t have a guest room? Do you let them sleep in your bed, or do you make them sleep on the couch? I’ve done both: I’ve been the self-sacrificial diva who lets my friends from out-of-town sleep in my bed while I snooze on the couch. More recently, I’ve been doing the opposite. I’m not sleeping in my own bed because I’m selfish, but because that’s what overnight guests seem to expect. Most people who are crashing at a friend’s place for free do not expect you to give up your bed for them. Of course, this is a totally different story if an elderly relative is staying over. Obviously, in that scenario, you would give up your bed to them. But if someone is young and able-bodied, there’s no reason you should feel pressured to give up your bed to them. 

You don’t want to share a bed with someone you don’t like or don’t trust. It’s common for families to make kids double up in queen-sized beds on vacations, even if their kids bicker about the arrangement. In a perfect world, nobody should feel pressured into sharing their bed with anyone they’re uncomfortable with. If your kid would rather sleep on the floor than sleep in the same bed with their cousin, something is wrong there.