This is the start image for the three previous creations on my feed. It's not meant as a 'show image' here as much as a lesson in the upmodeling process.
was noised at 50% with the exact same prompt as the start image
was evolved from the first linked image with the same prompt, and again noised at 50%
I went back to this pic you see above, added another 'fluffy' word in the prompt and noised at 10%.
Good example of how SDXL likes to make fluffy ladies thinner/more 'athletic'. I don't encounter this problem in 1.5 or 2.1, so do most of my work there.
When in doubt, go slow.