I can't imagine the binding is wider than the board at the contact points. Most bindings can slide the pedal out (the part of the pad where the toe-side rests) to adjust to large and smaller boots/boards. The boot hanging over can be an issue in some cases, but I wouldn't expect the binding to be a problem.
She wont have issues unless your pulling the front pedal out all the way assuming those bindings even have adjustable ones.
I ride a 24.3cm waist with medium(Size 9 boot) Cartels and have to pull the front out quite a few notches from stock.
'09 151 Never Summer SL-R
'10 K2 T1 DB Bots
'09 Burton Cartel Bindings
sweet, I figured it would be ok, but just wanted some second opinions
would you say that the unions are a piece of s**t or what? She's an up and coming rider, and doesn't demand sick response or anything. Her last board was a K2 ? (I dont even think it was a certain model, it sucked damn hard).