Lowering Pillion Pegs

My wife finds it painful to sit with her knees bent after a short ride. She had 2 knee joint replacements and can hardly bend her legs more than 90 degrees.  I need to lower the pillion pegs.  Are there any ready made lowered pegs commercially available?  Any advice in this regard?

Lowered pillion pegs? Not that I am aware of. 

But you might try Asian sources —mind you not that there are a lot of long legged folks there.

Maybe a seat cushion might just reduce the angle of the knee slightly.