Full-time Nanny For Infant In Potrero Hill

We're a family of 5 in Potrero hill, and our youngest, who is 6 months old, needs a nanny. We would like the nanny to play with him, take him to the park and to activities, and manage meals for him. We'd also like the nanny to take care of washing his clothes and organizing them. As a bonus, we'd like the nanny to occasionally take care of our other 2 children if school is out or they are home for some reason. They are 5 and almost 3. Being comfortable with more than one child is not required, but let us know if you have experience taking care of more than one child, and would be willing to do so when the need arises (say, 1-2/month). We'd obviously increase pay accordingly during those times.