It works as a short middle grade book. The politics, plot and side characters could have been more complex but their mediocrity stems from it being for younger readers. I probably would have liked it more as a child because seeing a book talk about things like third-child policies in a "child friendly way" is very rare while being executed pretty good. Honorable are Luke and Jen as main characters. They felt real and imperfect, creating an interesting and fun dynamic. The beginning was rather slow while the middle and end were paced well. 
Overall there was nothing horrible but also nothing great. I enjoyed some parts even though I believe it is mediocre. Still, I think that for younger readers this should work.