How about this idea then.

Hot,Cold,Wet,Rock,Breeze,Poison, Plant, Bright, Dim, Mind, and Body.

All of these are little symbols she can draw in a coloring book, and she was a artist in her previous life.

Threw the combination of these she cast spells, although the more there are the harder it is to activate, and draw. The more complicated words are also harder to activate and draw.

The better the drawing the more likely it is to work, and the more powerful the spell.

This allows for a bit of comic relief, cute loli is cute factor, and gives her that feel off burstyness as she can keep a certain amount of spells stored in her coloring book.