If you can get her to a shelter before the kittens are born, it's better for everyone. If not, I'm just like Hair as far as adopting needy souls off the street (4 legged kind).
I'm allergic to cats, so it keeps me from going overboard and since I've stopped working at the animal clinic, temptation is no longer in my face on a daily basis.
If you do keep her, put her somewhere quiet like a spare room or the garage, in a box or crate. She'll want privacy, but I believe that if she's sociable enough to let you pet her, she'll be alright with you all around her kittens. As a precaution, I'd keep Autumn away (look but don't touch) until you've tested the waters and the kittens are a week or so old.