1) Yes, it will likely affect your ability to rent a unit. An eviction doesn't just mean that she had, for example, some economic trouble some time and had difficulty making rent--to a landlord, it means that she violated her obligations and another landlord had to go to the time, expense, and trouble of removing her. A landlord will often be loathe to put her on a lease for that reason (I do a lot of landlord-tenant law, so I see this happen.) That's not to say she'll prevent you from renting, but she would be  strike against.2) You are not required to disclose her history IF you are not specifically asked (i.e. you don't need to mention evictions unless the application, etc. asks about prior evictions). If you are asked and lie and the landord finds that out, you could be evicted for commiting fraud on your application.