LingsterI like the stories to be realistic.
"Bang, there was a flash of light and then jenny was 9 feet tall and had 90 inch biceps [whataver the hell that would look like] She picked up the automobile and threw it at the house…"
Stories like that are so awful.
I know what you mean – unrealistic measurements annoy the hell out of me. Instead of writing "9 feet tall", it would work better if the writer were to structure it as, "She’d grown so tall that her belly button was now at the same height as his chin."
And of course an extraordinarily muscular woman at 5’4" (64") might have 16" or 17" flexed upper arms. At 9′ (108") I think you could scale up in direct proportion – from 64/17 to 108/29. So it might be better to say that "Her flexed upper arms had grown to the point where they looked to be nearly as thick around as his waist."
Useful devices to express growth include clothing and shoes tearing, heads bumping into things, relative observations ("I was now looking eye-to-eye with my formerly petite wife. I glanced down and gawked at her shoulders and arms, which had grown thicker and stronger-looking than my own, but when I returned my gaze to her face I found myself looking up to make eye contact. Not only was she more muscular than me, but she’d grown taller, too!"), and the protagonists own thoughts as she grows from weak-bodied to freak-bodied.