Full time nanny

My family and I have just returned to Australia after 8 years living in NYC. I have 3 kids 5,3 and 7months. I will be returning to full time work in September and my husband runs his own business so we are looking for someone to join our family full time to help with the kids. This would include caring for Polly (7months) 5 days a week, Gilly 3 days (he will go to daycare 2 days a week), and Heidi 2 days a week (she is in Kinder 3 days) but will need picking up at 4pm. In addition to this we would love help with tidying the kids things, washing their clothes and helping with some meal prep.