I'll just give my opinion that someone would typically check into their hotel first and then head out on any adventure -- unless they arrived really too early for check-in?
Unless they wanted to head for that area but didn't want to worry the taxi driver by asking to be dropped off in the wilderness.
Choosing a hotel, asking to be driven there, waiting until the taxi has left and then going on to where you really want is probably the most surreptitious way.
I'm presuming she doesn't have a tent and camping equipment?
Well, this is most bizarre! From Montpellier to Scotland. I do hope she'll turn up safe somewhere.