Higher seating position for Pillion on GS

[swartspan]

My wife enjoys riding with me on my 1200 GS.  She (fortunately) has nice long legs.  This unfortunately does not work too well with the pillion seating position of mentioned bike.

Does anybody know of a higher seat of "cushion" type that I can try for her to sit about 50mm higher?

 

[Adventurer]

 

[Grotex]

 

[Fudmucker]