9 years old and already converting her to the SS Dark Side.... sweeeeet....
Nothing else to offer since this question can't be answered without the clearance information asked for above.
Keep in mind too that this will also depend on how fast she's riding and how hard she corners. Not much lean doesn't require a lot of clearance. But if she's trying to drag knee on every turn then you'll want lots of clearance.
"dragging knee" being a motorcycle slang term...