[Outwardly, the only really noticeable difference is the spiky quality to her hair. There are no special hair care products making her ponytail look like the top of a pineapple. That's all natural. The eyes would be an indication, although hers are a bit different than what's standard for a Saiyan, being slate grey rather than the far more common completely black.

She looks mildly amused at the headbutting comment.]

I'm--

[She almost starts to revert back to her old habit of saying "I'm just", but she's beginning to gain a little confidence and cuts herself off.]

...definitely not someone who'd headbutt someone just for that.

[And she's not exactly tall, anyway, so she'd be far more likely to punch, or perhaps fly up and kick, if she did want to hit somebody. She sets her very full tray down at a cafeteria table when he asks about ki. A direct demonstration is probably the easiest.]

Um, well...ki is life force energy, basically. It's energy that comes from training and life experience.

[She forms a small ball about the size of a tennis ball in the palm of her hand. If he pokes at it, it will tingle, but she's not putting a lot of power in it so it won't actually hurt. It's just a bit of glowing white light.]