Our rescue dog has killed my other dog and one of my goats. I think that I either need to find her a new home or put her to sleep. What are your thought?

I have a Boxer that I rescued. The previous owner was terminally ill and had to give her up. Or that was what I was told. She seemed to be fine with all the other animals and then she got into a fight with one of my older dogs and that dog died from it.
Since then she has killed one of my baby goats and attacked an adult goat through the fence. I have been watching very closely and yesterday I saw him grab the male goat by the face and would not let go until I hit her with a stick. My daughters will not let my granddaughters come to my house until I get rid of this dog.

My question is: Should I try to find a home for her or put her down? This is a very hard decision for me.

Sharon