You could leave the L1 family stand where it is, no L2 available for family stand. The youngsters love to join in the chanting, not too sure parents will like them singing the songs when at home though
It is not feasible or fair to put youngsters in L2 or L3 south stand, anywhere near the away fans
The away fans won’t be moved anywhere from where they presently are due to logistics
I would make North and South stand cheap as possible. It will make for a great atmosphere if L2 is rail seated other than the lower tier