It's hard to introduce a new cat into a household .. espec. depending on personalities ... and they've got them just like people do. It would be good to allow her separate space before 'forcing' her to fit in with the group. She's got a whole world of adapting to do ... from the home, to the people, to the pets and the furniture, the smells, the sounds, etc.
It's like an orphan coming into a new home with siblings ... it's good to give them a space of their own till they adjust. Here's a link to a site that has a great animal behavior speapplest. A local contact for me. I hope you find more good tips there. Keep us posted how well it goes. And give that kitty a hug for me.
http://www.centerhillschool.com/behaviorissues.html