That post you link seems skeptical about her three start ups due to her being a political science major. But if you look at her LinkedIn account they appear to be actual start ups, just not tech focused. But it seems like the type of skill set that I would look for in a product manager.
People who go out and make things happen are rare. Regardless of major.
This interpretation rings hollow - if you've worked at any tech company, you've seen the hoards of people who manage to create meetings about meetings, grow their empire, and amass massive salaries with no relevant skills. A lot of it is about showing a record of "getting things done" - but things that don't matter.
If people are getting things done, but these things don't matter -- that's the fault of leadership. Leadership should have clear goals/OKRs/outcomes that they've agreed to. These people should be getting these things done. If they do these things and they don't matter -- it's likely not their fault.
And this applies doubly so for a junior product manager. I was not long ago VP of Engineering and if my team built stuff, using best practices and on time, but what we built didn't matter -- I couldn't blame them. It's my fault. It's my job to make sure what we build matters.
But if I can give a set of OKRs and you can drive to make those happen -- those people are gold. Now you can argue with me that the OKRs were bad. That's fine. Fire me. But the person that delivered it -- those people are worth their weight...
People who go out and make things happen are rare. Regardless of major.