A pistol integrated into the drone. (You reload it by inserting a Magazine into the where the cab section would be on a full size Tachi.) It'll probably be a Unity or something.
She can start with an early prototype.
Hiromi: "What even is this thing?"
Motoko patting a round flat disk-like drone with a Cut-o-Matic attached at ankle height and two googly eyes stuck on it: "It's a battle Roomba!"
I looked at my own chrome arm for a moment and realized how… inadequate it was. How badly they had restrained the power the arm could exert, to make it easier to quickly replace in a desperate situation.
Motoko: "I made a few upgrades to my arms, Hiromi. Now I can get the remote from all the way across the room!"
Motoko holds out her arm, palm out towards the remote and yells out, "GET OVER HERE!" as a long chrome tendril lashes out, snags the remote with three slim manipulator fingers, and retracts quickly until the remote is in Motoko's hand.
Hiromi: "..."
Motoko: "I managed to put three of them in each hand!"
Motoko drops the remote and extends three tendrils from each hand and waves them around hypnotically.
Hiromi: "I'm an Asian girl and I don't know how to feel about this."
Motoko: "Check it out, I'm spider girl!"
Motoko launches a tendril into the ceiling and tries to swing from it, only for the cheap construction-grade ceiling to fail at holding her wight.
Motoko from the floor: "I'm okay!"
A loosened light fixture falls down onto Motoko's head.
Motoko: "Still okay."