There is a lot of work going on in this area now as we become increasingly aware of the prevalence of autism in girls, and some of the difficulties in recognising their needs in time to avoid significant mental health difficulties at secondary age and beyond. 

Autistic girls may:

• hide some signs of autism by copying how other children behave and play
• withdraw in situations they find difficult
• appear to cope better with social situations
• show fewer signs of repetitive behaviours

This means autism can be harder to spot in girls.

(Taken from NHS website: https://www.nhs.uk/conditions/autism/signs/children/)