This is the most civil solution.
If you still can't resist HAVING A LITTLE FUN WITH IT, don't just put up a shading panel but a MIRROR. Have as much fun as you can setting its angle! :D
Also check local zoning ordinance to make sure her light pole is placed legally and not encroaching any set-back areas deemed unbuildable. People often forget to check this when placing poles and building fences. This knowledge will also help you place your panel.