Keep in mind the every time Ellie changes a man's size, so far, that's Chloe doing that for her.   At the moment Chloe is sorta taking a back seat while living out things through Ellie's perspective; much akin to how we did when we were kids using toys to give life to our imaginations.   She's taking a break from cosplay and buying clothes for herself while expanding Ellie's wardrobe and finding/making clothes for Ellie, and even clothes which they can share while Chloe is at Ellie's size.

       Chloe does do some growth again in both Chapters 7 and 8.

       Also from chapter 8, "For a brief moment she considered growing herself to a larger size, just for the opportunity to use her powerful strength to peel apart the car."
       Chloe isn't impulsive.  She could have destroyed the car but then the people they rescued could not have then used it to escape.

       Also from Chapter 8, "A breeze began to lift Chloe's hair.   She truly enjoyed these rare moments of being a giantess.      She had learned already that changing her size meant no more using hair bands or hair clips.   They’d just fall out, and she didn’t want to risk losing them while on missions, inadvertently leaving behind samples of her DNA.   Sometimes braids didn't work either, as the changes in hair thickness resulted in different tensions than at her normal size.   Each strand of hair went from normal hair thickness, to like the thickness of thread, or string, or rope, or cable thicknesses, as she got larger.   Right now her hair was behaving like a loose sail on a sailboat.   It moved in waves with a slow-motion kind of effect, like a really huge flag.   The strands of her hair ruffled in the wind with a low, bass tone."

       Chloe is yearning to be big but knows that she would be doing so at the risk of losing public anonymity.   She limits such times to the cover of darkness in remote areas.   She is not yet ready to go full Tony Stark and say screw it, I'm Iron Man.   At least, not yet.