Think about how you would like her to be spending her time - being realistic about what someone can achieve.
For us, with 2 toddlers (and slightly complicated by it being a nanny share and only 3 days a week) we knew that what we wanted was for the nanny to be focused on the children, not chores.
She does cook for the children from scratch, which is important to us and we made sure we discussed at interview. It's fab: she is a much better cook than me!
Apart from that, she tidies up after herself and the children, and picks up the odd bit of shopping or children's prescription. She doesn't do the children's bedroom, laundry, clothes sorting or buying. If a parcel is coming, she'll take it in if she's there, but we don't expect her to change her day to accommodate it.
This balance is our choice, partly because of logistics, but mainly because a person can only be in one place at a time, and what we want is for her to be playing with our 2 active toddlers!
BUT, if anything does come up, she's always really lovely and generous about offering to help. And the occasional time the dishwasher has finished but not been emptied, or children's clothes are still on the drier, she always sorts it out without making anything of it. We really appreciate her flexibility, and desire to help us - and it's not just about chores, but is fundamental to how she works with us. That's her character though, and part of why she is such a great nanny.