[Ashie!]

So there is a stray Pitt bull and I've been taking care of her. I named her Angel.
She was VERY skittish at first, scared, STARVING, and cold.
She has a scar above her eye.
She was so scared, but I gave her a treat and she followed me home.
I gave her a bowl of dog food and she dug in. Not even a min later, she was finished. I gave her another bowl and she ate it really fast.
I gave her some water and she would not stop wagging her tail. She was so happy.
I let her use my dogs' old bed and she sleeps in it and has blankets.
Her owner abuses her and the other dogs, you could see her ribs...
It is going to get down to 20*F later tonight. what should I do? Cinnamon is doesn't like Angel and Angel doesn't like Cinnamon.
I tried to get them to meet through the fence but they keep growling.
We brought Angel inside our house when Cinnamon was outside.
Angel didn't want to go back out but did eventually.
I thought about letting angel stay in my room for the night, she did pee in the living room, I don't think she's potty trained.
I think she I possibly 7-10 months old, I'll try to get a picture of her. She has a lot of scars and scratches. She is really dirty but really soft.
Should I give her a bath?
Should I let her in my house tonight?
How should I get her and my dog to befriend each other?
She is so sweet and loves to cuddle.
We live on a road where cars go really fast, and I don't want her to get hit.