Xin Ao, I am not sure if I am understanding your question correctly. But just going it a go because I recently came across a resource that seemed quite interesting. Have a look at this network and its resources: https://www.childrensresearchnetwork.org/knowledge/resources/gender-differences-in-cognitive-development-and-school-readiness

You can also add the following:

http://dspace.calstate.edu/bitstream/handle/10211.3/182893/2016JonesMarcia.pdf?sequence=3

Article Preschool Children’s Beliefs about Gender Differences in Aca...

It can be associated with growth, as hormonal changes takes place it may sppedup or normalize development in children.