I use a stock pack from here:
Cheap knockoff but it works and is well made. Comes in a couple differnt colors...
I bet you could cut a section of pool noodles and put it under the stock pack, the adjustable straps should be long enough to allow it.
But it looks like she needs a pretty high pad.
Ever think about not using the rail adapter?
That would lower the scope and probably make things more in-line...
The UTG integral scope rings work really good..