If she didn't get a pay downgrade to associate swe then she is not even remotely close to starting from scratch. The company is basically letting her learn a new field on their dime, which is fine, but this is basically a story less about her earning her skills as a software engineer and more about the charity of her Boss and the company allowing her to learn these skills.
This is not an economic move for the company. They are better off hiring a new CS grad, and if her pay wasn't reduced they are better off with a senior engineer. An action like this is literally an act of charity. People go through a lot to learn dev skills and she is being handed these skills as a gift.
What I'm going to say next might come off as a bit sexist and keep in mind it's just representative of my own anecdotal experiences and others may have completely different experiences.
I have found that when a female developer isn't doing so well on her job she's given a lot more leeway then a male developer. Additionally a lot more people (men) will go out of their way to help her because of her sex. Part of the fact she was even offered a role as a developer very likely has to do with some aspect of this.
Frankly, I can't see this same situation happening as often for a dude. Men are subconsciously judged more for their competency while women (especially attractive women) trigger good Samaritan vibes, making competency take a back seat while people do everything they can to foster a community of help and assistance.
Nothing wrong with taking advantage of it, but if I was a janitor in an engineering company and I asked the director for a starring role as a SWE they'd look at me funny. But if I was a really hot female... I can see the possibility of a director trying to establish himself into a mentor-ship role.
I'm not implying men do this consciously. I think most men and people in general like to think of themselves as non-biased so most of this happens as subconscious actions.