It was noticeable, to me anyway, that the police asked Kate why she didn't take the children to dinner with her.
The English are known for strict bedtimes, maybe relaxed a bit on holiday and special occasions but they don't usually take young children out to dinner.
I must say we always did when we were on holiday and, as someone said above, loads of other children were out with their parents until late. It wouldn't have occurred to me to put mine to bed and go out to eat without them. However I'm not criticising, I accept people feel differently about such things and require some adult time.