One issue that VegasJen has not yet considered is how would a new contemporary crank (either the inexpensive 12-speed one I linked above or an 11-speed model) work with her existing 9 or 10-speed drivetrains. Lots of variables there.

For example, I use 10-speed Shimano chain rings with an otherwise 11-speed Shimano drive train without issues, but she needs something else.