It sounds about right to me. I like to use 2 bags because I have main needs in 1 and additional things I might need in the other, which depending where I am going, I leave in the car.
Bag 1; cloth nappies
Cloth liners
Box of washable wipes
Spare nipper gripper (fab product to use instead of nappy pins)
Spare nappy cover
Wash bag for dirty nappies
Knickers, leggings, socks, T-shirt, cardigan (for 3yr old)
Trousers, socks, T-shirt, jumper (for 1yr old)
First aid kit, including arnica cream, nappy cream, lavendar cream, teething gel and the usual bump pad, plasters etc
Suncream
Diary, notepad, pen, mobile phone, hair bobble, nail file, lipsel
Sanitary products (still no period yet after 18m so any time soon I imagine)
Reins
Fold away shopping bag
Children's snack
Bottle of water
Disposable bibs
Disposable Detox wipes
Bag 2; sunhats
Waterproof coats and trousers for everyone
Mozkito repellant
Children's wellies
Children's fleeces
Blanket
Picnic blanket
Children and adult florescent jacket
I only have 2 under 4. Sounds loads when all wrote out in a list, but doesn't look loads. I have Phil & Teds pannier bags and although they don't look massive, they are pretty cavinase.
Having said all that I do have a repritation for having everything that could ever be needed in my bags.