Wouldn't a small propane powered stove (Coleman or equiv) along with a few bottles, be even easier and more effective than starting an open fire? I have the same issues with my MIL...
Having now read the entire thread, I see you have propane on site. Depending upon the size of the tanks, location, etc. it might be possible to tie in the stove permanently.
Thanks Hikermor. She's got a 100 pound propane tank tied into the trailer so, along with the bbq, she's in pretty good shape.
We did a coleman camp stove for her as a back-up though.

She's pretty comfortable using propane so I'm with you thinking that campfire cooking would be only a back-up for her back-ups. It was fun watching her remember something she did long ago though. Making your own campfire is very empowering!