Females can be just as aggressive as males, and sometimes more so.. some females just don't do well with others in a sorority. It is possible you have a male plakat, as they sometimes get mixed up. If s/he is aggressive, regardless what sex s/he is, it should be removed and kept in it's own tank.
I don't always use egg spots as the telltale sign, normally yes you can go by that to a point, but sometimes males have it, and even young male plakats have it...
Here is a link to a thread sticky in this section of tail types, since I saw your signature that you are unsure of what you have. Hope it helps.
Tails and colors list