Sure was! Cheaper by the Dozen draws from the actual events and dynamics of the Gilbreth family. It presents a fictionalized but still true-to-life account that captures the essence of their experiences.
Well, it takes some inspiration from real family situations, but it's also fictionalized and embellished for entertainment purposes. So, it's a mix of real and made-up elements.
I'm not entirely sure what specific analysis you're looking for. But generally, in a 'cheaper by the dozen 2 charlie oc fanfic', it might explore the character of Charlie in new and different situations compared to the movie. It could focus on his relationships, his growth, or his role within the family dynamic.
Family bonds are a very common theme. Just like in the original story, fanfics often focus on how the large family sticks together through thick and thin. For example, they might face financial difficulties or problems at school, but they support each other.