Hi!. we have 2 small house dogs & have adopted 2 other dogs also have to big dogs outside all the time the others do come in the house but they sleep in garage with other outside dogs.. the dog that has pit bull in it has attached the smaller dogs several times... shes been fixed & a sweet dog other than that, we do feed them separate. What is the correct way to stop her from doing this?. thank you,

Lots and lots of patient training, and it might be very difficult at her age, and you might not do it right, and she might kill another dog, sweet though she is. I don't think you can keep her with that many other dogs.

Your title says something else - what's that about?

How old is the pit mix that is attacking the smaller dogs? Is it one of the puppies or an older dog? Under what circumstances is the small dog getting attacked, over toys, territory, is he acting like a "big" dog and instigating the attack?
And what do you mean by attack? Rough play or is she really going after them? Both of which can end in injury
It actually seems that you have a lot of dogs, I'm counting 4 plus however many you have outdoors.
Get back to us with a little more info.
Are you willing to give up the one dog in order to protect the others?

The pit bull is 7months old.. she does not mess with the bigger dogs at all .we live in the country & most stay outside 100% of the time ,but the pit bull ,2 chuwawa's & one mixed dog do come in lay around & go back out after breakfast... they all sleep in garage!. They play a lot & most of the time she attacks when it comes to food.. (we do feed them at separte times)).. but she does attach if she thinks one of them Is getting to close to my husband at least 2 times a week this happens.. if we need to give her away that's what we will do to protect our family & other dogs..

7 months old and no training, and lots of other dogs. The question is how much time and effort you want to put into learning how to train her, and then training her? It sounds to me like she will be more of a danger as each day goes by, even if you keep her outside all the time.