Au Pairs and evening babysitting

[Metrobaby]

When does your aupair normally start their evening babysitting shift? At the end of their normal end time or at a specific time?

whenever the parents are leaving for the evening in my case. usually with the kid/s/ in bed.

As a live in nanny I tend to take a break in between babysitting and mb coming in then babysitting although I have also done babysitting nights when I just carry straight through

If it's the weekend, I get the kids in bed then go. If it's a weekday we both put the kids to bed as normal then I go, or I help her until I have to go if it's an evening class.