This is such a fantastic card, and is a ridiculous bargain. For one resource, you can remove a negative status card three times. Athletic Conditioning has the same cost, and only removes one status card once.
Yes, Night Nurse comes with a caveat, since she will also remove 'Tough'. But frankly, that is an almost meaningless concern. Her damage healing is just a bonus effect tacked on to an incredible ability. She removes negative status effects! Essentially freeing your hero to act a full turn early. If you're relying on the Night Nurse for healing, you've made many other bad decisions to get to this point.
Her ability and its cost is so broken, that they have not included her anywhere else...ever. There is a single copy of this card in everyone's library because she only came with Doctor Strange. At this point, even Cosmo (who can synergize with Strange in a ridiculously broken way) has been in more than one expansion.
The Night Nurse is an automatic 'include' in any Protection deck.