One on point note first, then something somewhat tangential:
Going aggro seems to have two related definitions: it's doing violence to someone who can't defend themselves and it's threatening violence to someone and being willing to back it up if they don't back down. Both of those were mentioned at times during this thread, though not succinctly and not as either/or.
my tangent is really that I seem to have a different interpretation of the Battlebabe than most people. To me, the battlebabe is a lot like War from the book Good Omens. Most of the time when you see War, it's not like she's actively doing violence to people, but wherever she is violence just seems to happen and it seems to leave her untouched. She just smiles lazily, finishes her drink, and walks out the door while everybody is busy blowing each other up. Looking at it mechanically, that's what the Battlebabe does best. She's magnetic, she draws everyone towards her, and then she does something that causes trouble and while the rest of you are screaming on the very edge of death she's calmly stepping her way through the minefield to rescue the poor little kitty, which was what she was after in the first place.
She's a sexy thing, someone that everyone kind of wants a part of, but the only way to get close is to step in the line of fire. And in a world as dangerous and nasty as apocalypse world already is, doing that is a very very interesting thing to do.
Anyway, just my interpretation. As has been said, you want her to be much more "combat effective" there are moves that cater to that.