Yes, he/she may, but it could have an impact on your family allowances.

A child aged between 18 and 26 (who is studying with an income) is regarded as a dependent child if his/her salary does not exceed the income threshold of 40% of the basic salary of an official in the first step of grade AST 1. (Amount after deduction of social security contributions but before deduction of tax, adjusted by the correction coefficient for the country in which the child is gainfully employed.)

Notify the HR Service in writing as quickly as possible so that will examine your file.

NB: Student jobs have to be declared to the HR Service.