I shaped a ball of foil around the loop on the head of the armature to reduce the amount of clay I would need to use which would make it lighter too. It did end up pretty heavy still due to the hair because I built that up gradually so it was just solid clay. The oven is a bit useless so her head got a bit burnt, but nothing a lick of paint won't fix.
Next, I used polyform to make parts of the armature solid. I added this to the pelvis so that the wire wouldn't move there, and to the shoulders. I also added some to the ankles because of the way the wire is bent... the plasticine model had problems because of that; it kept squashing so she wouldn't stand up, she would just roll backwards on her heels and fall over.
Last thing i've done at this point is to start covering the wire. Her arms won't be seen but I wanted to give them a little more shape under her clothes and protect the wire. I wrapped them in wadding and then very tightly bound it with cotton thread.