Parts required for swapping manual disc to power disc??

If she finds the pedal too hard to push, you may be able to meet her needs by just swapping in a master cylinder with a smaller bore. This will increase the length of pedal travel and make the pedal effort lower. If you're presently running a 1-1/32" master cylinder, the pedal will be stiff, especially if you've got any kind of a semi-metallic brake pad composition. Regular organic pads, prepared before installation as described here and here will make the pedal less stiff, as will a 1" or 15/16"-bore master cylinder.

I still recommend the smaller-bore rear wheel cylinders, which will also help.