I think row 9 seats C&H J &K would be a better choice for a family of 4 with small kids since you can see each other 9C & H are AFT facing seats,9J &K face forward so you'll be able to talk to one another easier & swap seats if needed and pass any items. 10 J K are AFT facing so it could be a bit more of a challenge to pass items with out having your seat in take off mode.
I find that there is more galley noise at 10 J K due to the chiller fans are on that side also the ovens. The most noise for 9C & 9 A & B is that due to lack of galley space the crew will use the crew rest seat area 13A B & 14 A & B for extra space for linens, glass racks etc.. There the last seat sold (coach type seats) to pax on flights that don't have a scheduled crew rest.
The nice thing about row 9 is that you're one of the first to be served.
Enjoy your flight .
