Yeah, that's way too low for any web purpose, but especially when you're seeking feedback from peers about file quality. Can you take the last three 100% crops again, and save them at Level 10 for upload?
The only complicating factor is the little bit of missing wing on the right side of the big girl. I had to borrow some other bits of wing to recreate the missing areas here:
That's right. Open the first image and extend the canvas size to the left. Add more than you think you'll need.
Then File>Place the second image. Then lower its opacity and fiddle with it until it lines up as best you can. Then mask.
Great. So in that case, I think your best chance is to use the left side of the second photo (including the bigger girl) and the right side of the first photo (including the smaller girl) and have the blend between them.
I can see why you prefer the little girl in the first photo.
But is there a reason you prefer the big girl in the first photo? She looks nice in both to me.