In SF it's actually a bit more nuanced than that:

https://sf.gov/stay-home-except-essential-needs "Are nannies permitted to be used? What about other in-home child care? In some instances. If the nanny provides medical/health care for the child, then yes. If the nanny lives with you, then yes. Otherwise, nannies not necessary for medical care are not permitted. Also, parents required to work away from home for essential services may need in-home child care, which is permitted."