i have an assortment of female peacocks in my main tank and they fight all day long non-stop. they even chase some of my males too! for a while i was starting to think they were sub-dominant males with little coloring however each of them has had a mouthful of eggs at one point or another so i know for sure they are female. so yes, females can be every bit as aggressive as males, especially with other femaies. they form their own dominance hierarchy just like males. about the only thing i haven't seen the females do is the shimmy shimmy shake males do when they are courting.