Great story! I love it when short girls grow big and this was a great exploration of character and psychology to boot! Fun premise, great dialogue, all very well-executed. One thing above all that I must commend you for is your efficient storytelling. This story is somewhere between a short story and a novella in length, but you do a great job of conveying a journey that takes place over the course of several months with a handful of scenes. The chronological gaps within the story are not remotely bothersome; on the contrary, I think it's fun to imagine what else has happened in that time. Finally: great ending. It's a good callback to the opening scene and a refrain from other points in the story. The final chapter hints at the potential future and further builds on the themes developed throughout the narrative, but it's not exhaustive nor definitive, which reflects the narrator's own uncertainty about what lies ahead. The cliffhanger is well-done and doesn't feel gimmicky or cheap. As much as I would like the story to continue, with Megan either persisting in her conquest of society or receiving a rude awakening about just how small she really is, I recognize that it's really beyond the scope of the core conflict and I think you chose a great place to end it. 

As this is a "review," I feel like I have to offer something more constructive, so I will say that some time skips could probably use some sort of physical indicator to demonstrate that time had elapsed. At a few points in the story you did this with asterisks (***), but it was not consistent. Thanks to the excellent writing, it was generally clear to me when a time skip happened, but it was somewhat jarring on a couple occasions and the inconsistency was odd. I remember it started to throw me off in Chapter 2, but as I recall it happened in a few places. Just something to keep in mind. It really didn't diminish my reading experience, but I think it's a minor stylistic improvement that can enhance your writing in the future. 

So I think Megan is growing faster then he can adjust. I think he really cares about her. And her attitude is changing/becoming more aggressive. There relationship Dynamics is changing. And I bet he is afraid she is going to out grow him. 

Let's see what happens in the next chapter.