Thanks all. Yes, it is 40K, but thought it might bring some inspiration.
It is Celestine, and the wings are indeed from Balthasar Gelt's Pegasus, though bent/curled a lot.
Here's a picture of the back as requested.

The backpack had the vents cut off and filed down flat. Then pinned, and finally green-stuffed a couple of extra feathers to make the joint look right. In all, the feathers are my favorite. I searched and searched to find feathered wings on the net and never found any that I thought were acceptable. Eventually, I had to experiment on my own to find something that looked realisitic. The shading looks more gradual "in real life".
Regardless, it could almost be a fantasy model if you snipped off all the hoses/piping and attached the wings directly to her back.
It never occured to me how difficult it must be to make a convincing joint to the wings in a fantasy model. If I were doing it, I'd probably have them sprouting from the armor itself.
Anyway, I don't frequent here often but thought I'd share it in case it inspired someone here....