I think if a sponsor was thinking about throwing money at an older runner, she would have to have some serious podium places at some serious races.
If I was sponsoring a runner, I wouldn't care about podium places. I care about eyeballs. If I had to guess one of the main reasons she isn't sponsored is that this is all new (2:35 last year was great but not exactly suggesting what would happen this year) and right now companies are struggling to figure out what their budgets will be going forward.
These days doping accusations are unavoidable. But history is filled with people with breakthroughs. I doubt all of them were doping.