Oh, I am hooked on b's and rescue and helping when I can. Also, the weather down here is "iffy" and when its cold/raining, the b's only want to be under the bed covers.
Re this girl. It sounds like she is trying to find her way in this house. So, let the dog you have show here the nice things, you as a human, be consistant, re feeding, potty items, and such. and leave her be.
She wants to see if she can trust you. YOUR family dog, the way they react to you, will give her a lot of info as to if your ok.
Just be kind, cool, and gentle.
Don't ask anything of her. I try to tell folks to be like you were in high school and liked someone, you just were around them, but ignored them..until they couldn't "stand" it and came over to chat. laugh.
Let me know how it goes. I think your on the right tract.