Nanny Primarily Responsible For Taking Care Of 5.5 Month Old

We are looking for a mother's helper/ nanny primarily responsible for taking care of 5. 5-month-old to give parents time with the two older children who are 6 and 12. We would prefer someone who could help out with light housekeeping. We would prefer a babysitter who does not smoke and is CPR certified. When not tending to baby, possibly playing a game/arts and crafts with older sister or helping prepare baby food/ snacks/ loading dishwasher/ etc. Timing is very flexible. 4/5 hours a day anytime after 11 a.m. 6/7 days a week is ideal but would be open to more hours if needed.