It doesn't sound particularly like she believed in the idea.
I think in retrospect it would have been better to offer 50% and the same salary as you.
Going forward though, I'd say definitely learn to hack. Also find people who might help not because of a salary, but because they think the idea is cool and want to be part of it.
Learn to hack. Giving any employee a hazy equity offer with promises to "scale it up" is a bad idea. The better your prospects get the more she is likely to feel screwed. And the worse they get, the less motivating the prospect of continuing seems.
Any scaling equity package should be linked to dates and performance goals. You basically said you didn't want her to own the company unless it succeeded, when success was contingent on her.
Sounds like she trusted you. Then stopped trusting you. Then left a few months later. You screwed up. Go apologize.
She wasn't initially hired as an employee - it was more of a contract agreement to develop the beta, with the option to come on as a full partner if we were working well together.
No one is saying learn to hack is the solution to the issue. Regardless of doing it alone, or finding a team, it'll be an invaluable tool. It'll help him play a more significant role if a team was formed.
It's not part of the solution here. It's just a good investment if you are running a tech start-up.
For example, if there was another partner here that knew how to hack, but wasn't a nurse, I'd say: Learn as much as possible about health care - it's your industry.
Either learn to hack, or find others who are passionate about the idea who can hack. Rather than people who are passionate about a salary. But doing both is a good idea IMHO.
note that she took a pay cut because she wanted a greater stake in the company. does that fit with her not believing in it?
it does sound like she didn't have the experience or the maturity to whittle down to an achievable project, however. learn to code, maybe that plus this experience will make you a much stronger manager and designer next time around.
I think in retrospect it would have been better to offer 50% and the same salary as you.
Going forward though, I'd say definitely learn to hack. Also find people who might help not because of a salary, but because they think the idea is cool and want to be part of it.