I think #3 is the best of this grouping. I would however, crop off that sliver of a doorway or whatever on the right hand side of it, and a litle bit off the top, just so the rock wall background is "clean", like it is in shot #4. I think you are getting better over this last month or so of photographing the kids. If we look at #1, with the oak tree, that's a bit of what's called an "incomplete pose"...she's kind of not posed "just right" and the shot is composed a bit "off-kilter", witb the large tree trunk kind of dominating the background, then the patch of pale, white sky, then the smaller tree.
Speaking of pale, white sky: that makes for SOFT,diffused light, which is EASY to work with, and which makes it fairly easy for shooting pics of a person who wears eyeglasses. I think the white balance is a slight bit too "cloudy", meaning about 300,350, or 400 degrees Kelvin too "high", for my taste.
The GOOD thinngs about shot #2 are: low camera vantage point, looking up at her; good expression and good eye contact from her, decent focus. I would CROP this one heavily, eliminating say 40% of the background, and it will be a bit stronger.
#2...NOT a good framing choice: girl in center, sitting oddly, too many leaves left and right, camera high up, looking down on her, her posture a bit leaned and hunched. Crop this down 80%, and make it a head-to-waist closeup of her. Her right arm behind the back makes it hard to crop to anything else except a fairly tight shot.
#3: cute, standing, half-body hand-pose. Very cute! best of the bunch, needs just the tiny crop top, and tiny crop right and then it;'ll be a good, simple, clean-backdrop shot, very pleasant.
#4...missing the hands, but otherwise, you did the best out of all four with this on the background, and the camera is low, which makes her look bigger. Now, this shot has the BEST, SIMPLEST, and most-pleasing background rendering of all four frames. PLease take note of how "clean" the background is!!!
YOU ARE GETTING BETTER James!!!! I can SEE it. Crop three of these an BOOM! Instantly decent. Not gonna rock the world, but still, a modern d-slr can stand some heavy cropping, and make some fine, fine prints! I thin k that getting to the point of #3 and #4 being basically, good, clean, nicely-done backgrounds shows a lot of progress. You might have more frames from this segment that you do not recognize as good shot, just "yet", since the shoot is recent, but 3,4,5,10 years down the road, you'll probably see more good frames than you do today.