Breaking from what we might call 'the life' can't have been easy; old home and new job may have been scant consolation. If she in fact was not depressed at all about the sudden shift, I would be surprised. It's entirely human to be.
In what may be termed a bit of dark synchronicity, at the time I read this one I was trying to recall the classic English car fire death/possible suicide case from the '30s --
UK - Evelyn Foster's fiery 1931 demise; finally found and posted it.
As well, a 20-minute internet search produced
over two dozen car fire suicides in the past several years. It sounds like something that doesn't happen often, and that's true. But it does happen more frequently than one would think.
And she was said to have purchased twice her normal amount of gas.
Finally, the solution is not currently disproved by either meager fact or copious rumor; and
I do believe the truth can be conveniently withheld -- supposing my view is correct -- in order to save the reputations of perhaps-scatterbrained LE.