I have a mate Who placed a large washer on the end of his peg to keep his foot in place after a major accident. Another removed the peg and left the tubular rod and insert that in the sole of his boot for track days
Have a look at highway pegs or second hand stuff on eBay Then you can modify these and put your original pegs somewhere safe for refitting in the future
Ok mate what about this? Get some flat one inch bar and cut it to size with an upturn at the end to stop your mrs foot from slipping off This could easily be held in place with a couple of jubilee clips Might not be pretty but nobody will notice and they could be removed easily without changing the bike at all mate