If you would like more specific suggestions to prepare the truck camper, tell us more about the one she will live in.
I.E. does it have a 12 v battery, does it have a cord to plug into 120 volt outlet? Does it have a 20 lb propane tank. Does it have a bathroom or hot water? Where is it leaking? How is it insulated?
As an example, if it has a shore power cord (120 v) then if she parks where she can plug in (friends driveway), she can use a small electric space heater safely. This might be the fallback plan when temperatures get really cold. If no built in shore power, she can still run a (heavy duty) extension cord for heat/charging. She can also use a battery charger to keep a battery charged rather than running the truck engine.
She is welcome to join the forum and ask questions herself here.
