Weekday Nanny For 2 Month Old

We're looking for an experienced nanny to help us out with our newborn. We're hoping to have someone start in late July, when he will be around 2 months old. My family and I live in New Rochelle, NY. We also have a 3-year-old, who attends daycare full time Monday-Friday. Our nanny will only be responsible for caring for the newborn during working hours Monday-Friday (approximately 40-50 hours per week.