I served beef to my kids’ babysitter, a Hindu. Should I tell her or is it wiser to stay quiet?

Maria cooked beef for lunch, a meal the family shares with the children’s nanny.

Maria cooked beef for lunch, a meal the family shares with the children’s nanny. But she forgot to inform the nanny, a Hindu whose faith forbids consumption of beef. Maria’s husband suggests they stay silent, as the knowledge of having eaten beef would upset the nanny enough to make her quit the job. But Maria cannot stop feeling guilty. What should she do?