Additional leave for children on two grounds

I am raising my two children, and this year I took another child into guardianship. If my eldest child turned 15 in February, but I am still entitled to additional leave for the entire year as a mother of two children, and separately — as a guardian. Please explain, can I really only get one leave lasting 17 days, and not two leaves of 10 days each? How should I correctly calculate and process this additional social leave for children?