~Sorry, didn't realise you had 4 children. How old are they?
Again, didn't realise she had different days to the au pair, that makes it different. Yes she should be doing the 'common sense' roles, no one has ever had to tell me to empty a lunch box or put a swimming kit in the wash for example. I had assumed from the previous comment that she was working alongside the au pair and was choosing to do her own role rather than the au pair's, if that makes sense. But emptying a lunch box should be just part of the daily routine if working sole charge! That's definitely not asking too much.
£50 a week is an immense amount of money! I get £10 if the parents remember, that's for 2 children one of whom is at home all day, the other does half days. I budget very carefully. That's for a 3 day role.
when I say schedule, I mean just the daily routine- In mine, due to activities, tea is at a certain time, due to the time MB gets home bathtime must follow tea immediately. I personally wouldn't want to work to a set schedule. I just mean- if pick up of child A, time to feed child B, etc etc leaves not much time to tidy it could be looked at. But if your children are older, they should be tidying. It'll be the nanny's role to get them to tidy, to encourage them to clean up after themselves.
If she isn't cleaning out a lunch box, maybe she forgot or didn't have time etc. It's something to be addressed but not immense. However- not cooking? No. that's something that is potentially leading to warnings, dismissal, it's that serious. I'm not a brilliant cook but my kids eat cooked food every day, I batch cook and freeze, I meal plan as I go.