Yep, you're right!
That first picture is rather flat, but the girl is so cute. I played this dangerous game with my little sister, unfortunately I don't have the references and she lives miles away from me. I took several shots of her and finished the portrait from life. The photos helped a lot, since she didn't stop even to breath.
I think you're on the right way, you need to work from as many references as you can and be careful about the values. Don't worry about working with photos of different positions and mood, all of them will help you a lot.