Help struggling student/ don't help struggling student--your decision.
But don't make the mistake of thinking that someone not doing well in those classes will "weed out" all those irresponsible horrible people who shouldn't even be in healthcare .
Read the stories on this site of people that struggle and overcome. Or struggle ,fail, and come back stronger than ever. Perhaps even a stronger better nurse for that experience.
You're not responsible for other student's sucesss or failures. But neither are you responsible for judging their fitness as future nurses.