* Individual differences: Children develop at different rates.
* Exposure to reading: Children who read frequently tend to be stronger readers.
* Instructional quality: The quality of their reading education significantly impacts their skills.
* First language: Children learning to read in a second language may have different developmental trajectories.
While some charts might suggest a specific grade level (around 4th-5th grade reading level for a 10-year-old), these are broad generalizations. A more accurate assessment would come from a standardized reading test administered by an educator or reading specialist. These tests provide a much more nuanced and individualized picture of a child's reading abilities than a simple average.