Flux in Joint and under 18 accounts

Question about flux. Got a notification to sign up this morning and did so, cool. No option to sign up with joint account, so Q1. If I use my joint account card will instill get flux receipts/rewards ?

My daughter has a Monzo card, she is under 18, no option to sign up to flux in her app Q2. Does flux integration work in under 18 accounts ?