The first thing I'll tell you is to try not to focus on the reading level. Within reason, of course. Don't go out and buy Crime and Punishment for your kindergartener. When your child brings you a book at the store or the library, don't discourage them by telling them it's the wrong level. For fun, at home reading shouldn't be forced into fitting a certain level.
If the book is "too easy" it might just be on a topic your child enjoys. Just because it's a breeze for them to read doesn't mean that they aren't benefiting just from the act of reading for enjoyment. If the book is "too hard" this is a great time for you and your child to work together to read the book.
Reading levels can tell you a lot, but they can't tell you how much your child enjoys reading. Never be discouraged by a "low" reading level score. Maybe your child was having an off day or they were otherwise distracted during the test. Pay attention to what your child can tell you about the book they are reading for fun rather than what an arbitrary test says they might be able to tell you.
If you are worried about your child's reading, the best thing you can do is expose your child to as many books as possible. As a parent, modeling your own reading is a great way to encourage your child to read. Reading aloud to your child, even after they are able to read on their own, is also beneficial. Try to keep it as fun as possible and not a chore. It may take some time to figure out the best books that work for your child which is why the library is an excellent resource for readers of all levels.
Emilie is a high school English teacher with two children. She holds a Bachelors in English and a Masters in Secondary Education. After completing student teaching at an urban, Persistently Low Achieving (PLA) school, she was placed at another PLA school in the same school district. Her Ask a Teacher column can also be found over at Teaching Ain't for Heroes.