Nanny Needed For My Children - Full-time / Part-time

We are looking for a nanny for my 2, potentially all 3, of my children in Westwood, ma. My 4-year-old is in school part time, and on his days off he will mostly be with me, but would like someone comfortable with 1 and 4-year-olds so that we can switch off and I can have some one on one time with each of my kids :) We would prefer someone who could help out with light housekeeping/easy meal prep for kids. And who has their own reliable car. We have a dog. No smokers please!