An au pair will work for up to 30 hours a week which can include up to 2 evenings babysitting. If you require additional babysitting then this should be paid at £4 per hours.
They usually work 5 hours per day, five days per week with 2 days off. Exactly how the 30 hrs are spread across the week is down to you to negotiate with the au pair.
He/she would expect pocket money of a minimum of £80 per week , all the food they need and their own bedroom.
A couple would suit a family who may have separate accommodation (although this is not a must) and need many more hours.
This is basically 2 au pairs with regard to hours and pocket money, so you would have 60 hours per weeks including babysitting. The girl would generally assist with the children and the house and the boy would maybe help with the garden, animals and driving duties although how you split the duties is your choice.
Couples are usually very flexible and happy to put their hand to a wider range of duties.
The au pair IS NOT an employee or a professionally trained cleaner, domestic help, child minder or Nanny. They are not capable of running an entire household when parents are absent for business or personal travel. Responsibility for the welfare of children always remains the responsibility of the parents.
Please go to Au Pair General information page to find out more about an Au Pair