Landlords can issue something called a section 21 notice within a fixed term to end at the end of a fixed term (provided the correct notice is given to tie in with rental periods, veryyyy easy to get wrong by not putting words like 'after'). It is a no fault notice and gives two months notice for a tenant to leave the property. You don't have to do anything 'wrong' to get one. Often they are used when the person wants to move back into the property but they are also very often served alongside fault notices (eg section 8's) as some of the grounds can be destroyed before a hearing (e.g. evidence of non repair). Section 21 is a mandatory possession ground where issued correctly.
My points earlier were that most are drafted wrongly and can buy you more time.
Effectively though, if a landlord doesn't want you in their house, you'll have to move out. But these things can be dragged out for a loooong few months if you need the time to look for another house.
Come back if you do get any notice to quit as it'll probably be written wrongly, lol.
Plus, if she does anything you know to be wrong (eg verbally asks you to leave or gives you an invalid s21) don't correct her until you have had advice as it can buy you more time.
Plus, if you paid a deposit, is it protected/have you got clarification of the deposit scheme as applicable? (applies if your tenancy started after april 2007).