She notice the changes, but no one else

What would be the point of making such changes if she doesn't notice it ? You make her aware of the changes. So, when her breasts inflate like balloon she panics.

"What the hell ?!?" She yell.

As you look from a safe distance, you see her look at her new globes sprouting from her chest and weight them with her hands. Even from where you are you can see how massive they are now. In fact she seems unbalanced with them hanging like this, so you decide to give her a big bubbly ass on wide hips, and wink.

Focused on the more visible changes, Diana doesn't notice how much of a bimbo she looks now with her hourglass figure. She instead rush back home in panic, leaving you laughing alone in the street.