Not part of her lease.
The owner just asked her to move out instead of allowing the other roomies out, in which case, he claims she would be responsible for the full rent. (Not likely, iMO, since leases in the Boston area to such disparate groups usually makes everyone financially responsible for everything. If the other roomies move, they are still on the hook for rent due. I’d be surprised if the owner can let the roomies move out and then make her responsible for the whole amount.)