I'd go with the IR light idea, which is brilliant. Rig up an IR light source and mount it on top of the fence, pointed at her camera. It'll completely screw up her camera image, but there won't be much, if any, visible light. We used to have an IR camera set up as a baby monitor so I know those are very sensitive to IR lights (remote controls, IR light from a video camera).
There's always the slingshot option, too.
There's always the slingshot option, too.