Also doing it out of a paid-for shared workspace. I mean, I love the stuff she's doing, it makes sense that she'd be able to do it working full time, but she must be independently wealthy to be able to afford it.
I know nothing about Jennifer or her lifestyle. But it is not that hard for a young, single person whose main activity is being productive to save up 6 months of living expenses.
Use of shared desks costs like $200 a month at places like Citizen Space, so it's not like that's a bank breaker.
If she had a family it would make less sense. If she were living a 'baller' lifestyle, drinking and partying every weekend, it would make less sense. But if she's an unattached workaholic, her life probably costs very little and no independent wealth is required.
I know a fair number of people who have retrained at University for another career, for example. Most of them weren't independently wealthy - they'd just saved up enough to be able to afford to go to university for a year.