Name of a satanic nanny ......old horror movie?

It was old but in color. The thing that struck me was the ending. It had a satanic or evil witchcraft practitioner nanny and she wanted the familys baby. The ending was her meeting another person, like insinuating the story will repeat all over again with this new pray. I know that is not much, and I hate when people ask stuff here with vague details but I can't remember anything else. Could be from the 1970, 80.. not after 1997 for sure. It's not The Omen, Rosemarys Baby or The Guardian. I need to watch this again, I just need to!