Hey,Deanna:
You did good! Especially as you were in the midst of a gaggle of other photogs.
Not an ideal situation, and certainly no place to start slinging elbows.

Leave that to the newsies. Your fill flash worked well.
Something I learned in a NIkon lighting seminar this week end...like your second image of the three girls.
Start the posing with the subjects facing about 30 degrees camera right or left. That's to avoid linebacker shoulders, especially with the young ladies. Then, have them twist their bodies slightly towards the camera, not enough to be uncomfortable, and shoot away!
Of course, that's not possible with a dozen rabid moms and dads ALL demanding "Look
this way, or do this, that, or the other thing, without regard to others present. But, one day, you will be the chief photog, then you will be able to direct your client (even if it is your son

) to the best advantage.
Be aware of your bakground.
Another thing, also learned at the seminar:
everybody has a "good" side. I knew that, but hadn't ever had anyone tell me what made it so.
We humans are not perfectly symmetrical.

One hand and foot are always larger, and other things are always slightly higher/lower/larger/smaller than the opposite number.
One eye is aways slightly higher than another. High eye towards the camera. It'll look better, if only slightly. At least, according to the Nikon tech.
Looking forward to seeing more of your work!