I hope this discussion is still active. Wonderful woman, my wife, but she can react to something she does not like and attack other dementia patients at facility I live in 24/7 with her, but impossible to keep up with her all the time to prevent "problems."
Before thinking about placing your wife in a different facility, take your wife to her primary doctor to ask about pills that could calm her down. Hopefully the first prescription will work, but don't be surprised if it doesn't, and something else would need to be prescribed. Sometimes it can take a month for a prescription to start working.
Another thing, have your wife checked for a Urinary Tract Infection. Such an infection in someone older can cause that person to act violent.