Sorry, I have zero experience in this child care / au pair business but I believe that its pretty standard what an au pair is.
According to wiki:
"An
au pair (plural:
au pairs) is a foreign-national domestic assistant working for, and living as part of, a host
family. Typically, au pairs take on a share of the family's responsibility for
child care as well as some
housework, and receive a small monetary
allowance for personal use."
The monetary allowance will be according to Kanton Zurich's guidelines. I understand it differs from kanton to kanton.