Poor girl. You were never in the running...
This manga is such a fantastic one and I hate that it just is... dropped. I wanted to see it continue to an end. The translated novels stop at chapter 35 and this makes me sad cause I genuinely love the characters and want to see what happens next...
I suspect she wasn't a doctor. It's just that she took a school health class and that usually carries the basics behind nutrition and whatnot. So what she would consider basic stuff kids learn in school is revolutionary stuff in the world/time period she lives in now.
And yeah, I agree that...
I like to think that in their previous life, the Villainess and heroine were in love with each other. Thats the vibe I got from their reactions and her wording