This isn't exactly what I originally planned, but I knew if I made Noah a student, there would need to be a teacher. My original plan was for just the traditional old guy, but I thought this could work better. It's kind of funny, and it helps the story seem strange without being totally unbelievable.
Also, "Professor Kidd" will end up the boyfriend of the other character who will be growing- Max's boyfriend's sister, who will be introduced in chapter 3.
This is chapter one, and it ends when Max has grown a certain amount and her boyfriend returns. Then chapter two is about introducing her boyfriend properly while Max continues growing. In chapter three, Max is at least bigger than her sister, and her boyfriend's sister moves in with them to go to college. She ends up sort of Max's sidekick.
What happens on the next page is that Max is given 8 gumballs. She's told to only take 4, one now, and then one each of the next days. She had duplicates in case she loses one, but taking more than 4 doesn't have any impact and would just be a waste. The extra four end up going to Sasha, her boyfriend's sister- who takes them knowing what they do probably, but without Max's permission.
I think Max will have three milestones, one when she's bigger than Sam, one where she's bigger than her Mother, and then possibly who ends up the biggest- her or Sasha (the underdog).