Congrats Goulum, you turned Edwina into a butch Nalia
What you have to do is resize the dimensions of the image to match the size of the portraits used in BgII (don't know what they are though). I'm sure there is a way of replacing Edwina's current image by putting it into the override folder, but it slips my mind atm, but what you could do is just put it in paint, make sure it is saved as a 24-bit bitmap image and when that's done, change his portrait in Shadowkeeper.