She says she wants to avoid gas or liquid fuels...
That sounds like your choice is thus narrowed down to ... a standard BBQ grill and a ton of Match-Light (no charcoal fluid required) charcoal briquettes and wooden matches. Nothing wrong with that. But "no gas or liquid" eliminates most other choices.
Personally, I would go for a Coleman propane burner stove, and one of those tailgating propane grills, feed with a couple of 20lb propane cylinders and an adapter hose. The fuel would last a long time and you'd get to cook more or less "normally", even using you standard household cookware. Many many people use propane BBQ grills safely, but of course there are a few nimrods who manage to blow themselves up. Still, I wouldn't let that deter me from using propane. Just learn how to use it safely. Millions of people do exactly that, every day.