I think she's got several different things going on with this one idea and she needs to separate them out and decide what she really wants.
1. She wants a man to teach her the ropes of owning and driving an RV. This is probably not best done while on a cross-country trip. Better option is to spend several months at minimum doing local short trips and getting the hang of things, and getting help from friends, etc. on how to hookup, dump tanks, etc.
2. She wants a man for companionship while on the road. I see many things to consider here: why must the companionship be a man? If she doesn't want a "romantic" situation, then wouldn't it be easier to find a woman companion? How are they going to sleep in the RV? Will they share a bed? Will the companion need to use a tent? Is she prepared to walk past the companion in the middle of the night in her gown to use the bathroom? Is she prepared to hear every noise the companion makes when he/she's in the bathroom? There is companionship and then there's living together...
3. She wants to drive cross-country in an RV. Does she really want to do this now as a single woman? Or is she envisioning the trip as she wanted it with her husband and thinks getting a male companion will make it that dream trip?
If she can separate out these things, she might be able to find what it is she really wants (and why she wants it), and then can start making real plans to do it.