What is your definition of a good nanny?

dear husband wasnt very satisfied with our current nanny cos he finds she's not as good as his mum.

But I'm comfy with her. We click, she takes my instructions seriously, she takes real good care of dear son, is willing to heat up my EBM for dear son(hear of some who throw away EBM & give FM instead). Everytime dear husband's relatives praised nanny for doing a wonderful job in feeding dear son, dear husband & his mum not shiok to hear them.

So what's your definition of a good nanny?