It's not unrealistic.
Is it extremely uncommon? Yes, definitely.
Might Helen need Victoria's wheelchair in the future, if she didn't train enough lower back? Possible.
I didn't change her boobs.
What was changed is just the dress, the angles & perspective.
Helen won't be changed.
I want her to be extraordinary. She's closer to one extreme in that regard.
You don't like how she currently is?
Sorry, but tough luck.
There are enough other girls with far smaller bodies/tiddies, and if they're not of interest to you, there are enough other games to play.