6mo & 4.5 years but will be shared duties with grandma(s) majority of time will be spent playing with 4.5 year old and doing/planning fun crafts and activities with her. Only duties with the baby would possibly to assist with nap time. Mom and Dad work majority at home so they help with meals but light laundry or housework or errands when the time is available would greatly helpful. One grandma would likely always also be there during these time slots so 95% of your time would only be one kid.