It is reasonable if she is a good nanny. Means she cook and clean the house in that 10 hours, so you don't need to do much house work. Negotiate this with her. If you are happy with her after the first couple month, when she takes one or two weeks vocation, pay her to keep her around. My personaly experence, it is hard to find a good nanny, once find one, you will definitely pay extra ( at least 1 month of salary) just to keep her.