I work with lots of psych behaviors and this is a fairly common occurrence in my facility, we get a couple throughout the year. I have had only 2-3 cases where we sent them to the hospital to be detained. Most of the time, you give the aggressor a PRN, if she doesn't have one, you ask for one. Sending her to the ER is not the correct answer in this case, in my opinion. Dip her for a UTI, give her a PRN. Good job in keeping them separated.