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

We are looking for care for our 18-month-old and 4-year-old starting in late August on Tues, wed and Thurs. Our 4-year-old will be at preschool most of the day but will be home in the afternoons. We are flexible on exact start and end times but are looking for 3 full days per week, preferably Tues-Thurs about 9am-4 p.m. Responsibilities include keeping the 18-month-old engaged, feeding lunch and snacks, diaper changes, putting him down for nap, and also looking after our 4-year-old when he gets home from preschool. The only light housekeeping needed would be tidying up after kid(s) lunch and keeping the playroom clean.