Chinese Crested Girls Always Fighting

Hello, I have two chinese crested girls, a boy chihuahua, and a toy poodle girl. One of my cresties is always attacking my smaller blind crestie. She has no way to defend herself and doesnt understand the pack order because she cannot see anything. My chi is actually starting to defend her when my other crestie attacks her. Its to the point where every time she hears her come close she starts growling and getting upset. Not sure what to do. I dont want to get rid of any dog as they are my family.

Crystal