Beautiful image to be sure ... and a gorgeous baby girl.
I wonder what it might look like if you mask the first image's eyes (especially irises and eyelashes), onto the last image's body. I might also try to clone away the black marks on the shirt at the bottom, and maybe clone-stamp some of the pink knitting on the shirt to get rid of the little gaps.
Also look into the area just around the baby's head, if you turn the brightness slider all the way down you might see a funny looking halo. With high-key photos, I try (but don't always succeed) to get the background to be slammed-out, retina-sizzling 255 white. Unless it doesn't work, then I don't
Again, the image is beautiful precisely as it is. ... just things to try.