Quick Q re child staying on at school 16+

Hello - hoping someone can clarify.

My daughter turns 16 on April 2nd.

Child Benefit sent me a form to confirm (or otherwise) that she would be staying on at school. (She's currently in S4, and plans to complete S6).

I've completed the form accordingly.

My Q is this - Does this form satisfy Child Tax Credits too, or is there a different procedure for informing them given that CB and CTC are both administered by HMCE?

Anybody know?

Thanks in advance for any help.

BiB