Renting rooms out.

Hi,

This is a bit of an awkward one but here goes.
I part own a house which I dont live in anymore. Girlfriend and kids inhabit it at present. Im still paying half the mortgage and my name is still on the deeds.
Can she rent out a room to another party without my permission? If she does and receives money am I entitled to half?

Thanks

Sounds like one for the lawyers but if she can it will be a source of income for her and should be reflected in any maintenance agreement you have.