Whatever you want her to draw. Make it appropriate.
doodle, scribble
i think you should draw a worm
you take a pencil and you doodle.
i think you should draw a worm
doodling
A cake that you can draw on
draw a doodle of the thing and try and try again.
"DOODLE"
Rather than draw a horse rearing, I think you should draw her favorite horse for your friend's birthday as that way it will have more of a personal meaning.
doodle
draw random things
The word is doodle.