Does it matter how old your main character is?
Absolutely. This isn’t adult fiction where your main character can be just any old age. We are writing children’s books, and children’s books have very specific age ranges for specific types of novels. They are:
Reader: Age 6 or 7 or 8
Character age: The same as the reader (usually). So, a six year old reader would read a book about a six year old character. (There are of course exceptions to this, but this is the general rule.)
The reason for this is that kids this age are very ego-centric. They want to read about kids just like themselves. (It’s also why diverse representation is so important— not just for this age but for all of them.) So, kids this age don’t really want to read about older or younger kids.
Reader: Ages 9-14
Character age: 10-12 (with a few 13 or 14 year olds in the upper, upper middle grade books)
At this point, kids typically don’t want to read about kids like themselves anymore. They want to read more aspirational stuff. In other words they want to read about characters they would want to be, which in character age, translates to older characters. It’s one of the reasons you don’t see many nine year old main characters. The eight year olds don’t want to read about them because they are too old, and the nine year olds (and up) don’t want to read about them because they are too young.
Young Adult (aka YA):
Reader: Ages 13-18 (There are some books that cater to adult women, and there are some kids as young as 11 that read YA regularly. But in theory, these books are supposed to be for teens ages 13-18.)
Character Age: 15-18 (usually. Sometimes you see a 13 or 14 year old or a 19 year old. The cut off is really the summer after high school.)
Like with middle graders, teens generally prefer to read about other teens that are older, but they aren’t quite the same sticklers. You do find older teens (and adults) enjoying YA books with a sixteen year old. You have a little more flexibility here, but the main character should still be a teen.
If you are writing a book for one of these markets and your main character does NOT fall in that range, take a hard look and consider WHY that’s the case. And then decide if that reason is one you want to defend, because you will have to defend it. There can be very good reasons to be an outlier to these general rules, but if you are, you will need to justify it.