I think credit checks can go on a number of things. If a previous resident of the house is blacklisted, then it could show on the address. A credit check would show it, as McCluff says, and it's something you can get amended.
The fact that the girl lives in rented accommodation can also go against her, I think, depending on the type of loan and the terms. It's a sad and ironic fact with credit that the more money you have to start with (so the less likely you are to need credit), the more easily you can get it.