I point out it's interesting you say that, considering the amount of people who seem (I am presuming) up-in-arms that the Moab police even considered leaving Gabby alone in the van due to danger.
I mean, we still have people, yea verily, even single women, who pull to the side of an authorized road, park, etc.; and catch a few z's.
Some women indeed still road-trip on their own.
And, last but not least, it wasn't until very recently when we started worrying about the environment vs. wholehearted "car culture", that Americans started moving away from seeing their cars as their sanctuary/equivalent to freedom.
For all we OR the Moab police knew, AFAIK, Gabby was perfectly comfortable sleeping alone in her van/choosing it instead of a hotel room; thus I don't necessarily think they did anything wrong by giving Brian the hotel room and ceding her the van instead.