temants broke up and one wants to leave !!!

new landlord asking how to solve this issue, thanks ahead of time.
Background: Boyfriend, makes $100K per year, and girlfriend, a stay home mom with their baby rented my house in May and they both signed the contract for one year.
Several days ago, boyfriend sent me an email and stated that they broke up, and he will not pay July rent fee and will move out in one week. Also he told me to ask for rent fee from his girlfriend, it is up to her to continue to live at my house or not.
Questions
1 Can he move out without penalty, how much is the penalty I need to ask , 1 month, 2 months?
2 If girlfriend can't afford to pay the rent, can I evict her? how soon? (I feel bad if I have to do that, but I need this to cover the cost. )
3 Even girlfriend can pay this month rent, she might not afford in the future months. I don't want to deal with this mess every month, can I canceal the contract and let her go?
Thank a lot.