I would have chosen Auberge du Soleil when I was there last year if they accepted children ( for me, might be perfect for you!). It has lovely views and is tucked away off the main roads (big plus in Napa IMO). If you want picturesque I found the scenery improved greatly once you got north of Yountville. Definitely try to get a table for lunch or dinner at The French Laundry! It is worth the effort required to secure a reservation.

Sonoma is drivable from Napa if you don't feel like changing hotels or can't find two that meet your requirements.