Great shots, and fantastic use of fill light, especially for just starting to dabble.
I'd agree with Don's assessment on the shadow from the hat, but this can actually be beaten a little bit with LESS pp work with some off-camera flash in a shoot through umbrella or soft-box (an area where I'm starting to dabble as well) shot at the right angle. You can also make sure that you position yourself so the flash is at eye level instead of above your subject, which is something I often forget as a taller photographer. Then you start running the risk of people looking "down" too much, so it helps to have a helper behind you to say "Look at me", then "lower just your eyes toward the camera". I've found the off-camera flash to be easier than that, though.
Now, having said all of that, realize this: I'm just sharing what I've learned since dabbling in the same area, and the results you've posted above are... FANTASTIC! Great mix of fill flash with the natural light, especially the 2nd shot of that original set, and the 1st of the 2nd set you posted. I'm guessing those were in a more shaded light than the rest as well? I've been asked for advice, in the past, about shooting fill flash outside, and I've always stood by the practice of starting out under-powered and working your way up into a nice light, where many do the opposite and end up with a bit of overkill... but it sounds (and looks) like you took the right approach and nailed it right out of the gate!