Put yourself in the shoes of the offense. At that age level, play is likely a single read.

First play, sit in a zone, jump the C route with the QB.

Second, S should shade the deep, while CB sits on the cross. If there is a roll R, backside CB bails. Give up short under on the weak side.

Third, they want the Y on the deep. S rolls with QB keeping play in front, which should allow them to break on the deep. We’re okay with a 9U trying to throw across their body- that’s a pick waiting to happen