I seriously doubt that anyone, anywhere in the world, would make one for the SV. It's just not that kind of bike
What's wrong with her using the grab-rail like everyone else? Tell her to cross her hands behind her, so her palms face backwards, and then grab the rail. That way she'll be stable* under both acceleration and braking.
[* does not include situations of near-vertical wheelies or one-handed rolling stoppies - neither of which are big or clever and I'm sure you don't do 
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