is lack of utilities electric, water enough to call CPS?

Why would you post this on an internet message board instead of immediately calling the police?

She could be one of the thousands of missing kids in this country. Please call the authorities and tell them what you told us.

If you are wrong, at least someone will learn of their living conditions and get some help for them.

CPS, local police, whatever. You need to report this immediately.

I've lived off-grid (no utilities) and knew of several other families that did the same. Lots of off-grid families include children that survived into adulthood much better than the suburban children that were neglected by their parents that were too busy pursuing careers in the big city.

To claim neglect strictly because someone is raising their children off-grid shows a level of prejudice I find almost alarmist.

Cool your jets. If the girl is being abused there are lots of signs much more significant than going 'potty (both ways)' in the woods and living in a home-built house without utility generated electricity.

Rap

My advice to contact authorities comes mainly from these two statements that I think are very significant:

Absolutely. I, too, have lived off-grid for lengthy periods in two totally different venues; it's not about that. There's something suspicious about the behavior of this pair as the o.p. has indicated. I believe the authorities should take a quick gander here.