Charlotte didn't actually have that clear of an idea what Quidditch was, and it didn't seem like their flying teacher would explain it.  What she [i]did[/i] know was that witches flew on brooms, and she was a witch.  And she knew that climbing a tree could only get her so high.  So there wasn't much to do but fly on this bloody broom, was there?  She smiled at the mild curse and held her hand out, with all the confidence of someone who had already rescued a damsel in distress today.

"Up," the broom jumped up, seeming as eager as she was to get into the air.  She threw her leg over and didn't wait for another signal to kick off.

Her first flight was unsteady and random, but the broom controlled intuitively.  You leaned where you wanted to go, and she used this simple control scheme to narrowly avoid Ajax as he whizzed by with a much more impressive stream of curses than she could muster.  

"Hey!" she called after him, and leaned forward to jet in his direction.  She reached him a few feet from the ground, and grabbed the arm that was gripping his broom to steer him back upwards.

"That was pretty dumb Aj," she taunted playfully.