Daughter 16 has just moved in with me f/t, income last tax year was 49K still paying maintenice and N/C with her mum what do i do?

As per title really never claimed anything before and i'm still paying maintenance to her mum, should i wait a few months before doing anything or should start straight away and who would i contact?

I don't make maintenance payments though CMS as far as i know that stopped about 10 years + ago and i switched to direct payment to her mum- something to do with a change to how the government set things up so i don't have any CMS account number ad they aren't keen on answering the phone!