Rescues or shelters that take newborn kittens?

My friend thinks a cat gave birth in her backyard last night. There are two newborn kittens there now, one appears to be dead and the other is still alive. There’s a black cat staying nearby the kittens; she thinks that’s the mother, but isnt sure. What should she do? Is there anything she can do in the meantime to keep the cats safe? Anyone she should call?