"Perfect Health"
 

A plot device that usually is carried out through magic, the woman is guaranteed to stay at peak health at all times. Usually this involves becoming instantly fit and athletic, and getting radiant skin and a fresh look. Depending on the author's tastes, many other things can be considered "less than optimal health". Like skin blemishes, rashes, or even sagging boobs!

Since health declines with age, the Perfect Health bargain may lead to eternal youth, instant regeneration/healing and immortality.

Taken to even more extremes, anything that didn't develop optimally at puberty due to malnourishment or genetics could be retroactively fixed, resulting in a taller, more well-built (dare I say bustier?) woman with a great bone structure. So it borders Increased Beauty.

Here's a story with some Perfect Health in the middle.
Seven Deadly Wishes 2

Got any more?

Re: "Perfect Health"
 

I also remember a story, maybe at www.fictionmania.tv, where a man was granted the wish to be able to heal any ailment, and then he learned that he could use it to basically resculpt people completely. He changed himself into a woman so he wouldn't be recognized and then started visiting hospitals and healing everyone... It might have been called "The healer", but I can't find it anymore.

Re: "Perfect Health"
 

Oh man, nostalgia. I believe that was on an old genie-centric TF site. I don't know if it's still around though.

Re: "Perfect Health"
 

The Chapford Wives

Three wicked girls in the 17th century made a deal with a demon for beauty, eternal youth, wealth, and permanent health, and have been perfect young women ever since. They regenerate injuries instantly.

Re: "Perfect Health"
 

The story was titled Absolute Power. It wasn't at Fictionmania, but on Joan's Story Site. I'll provide a link as soon as I can find the site again. I was using a link from a now dead site.