At first I thought that It would only last a few days at most but it's been 2 weeks now and It's making life a little bit difficult for me. I don't know this person and since she's essentialy downstairs all the time I'm just scared of going downstairs to do things like cooking. 

I've asked my mom how long she's going to stay but she doesn't know and I don't know how or even if telling her that it's making me uncomfortable. I keep thinking that maybe this friend has had issues and is without a home now and I wouldn't want to make life more difficult for her plus I wouldn't want any conflict with my mom since we don't have the best of relationship. Idk how to solve this, any advice ?