Why did Hermione stop Ron & Harry from running from Lupin when he turned into a werewolf in Prisoner of Azkaban? She is very smart, she herself said a werewolf would turn it's best friend.

I think that she stopped them because she heard Lupin whining and cowering a bit. It was an unexpected reaction from a werewolf, so she might have thought that unlike what she'd read up on werewolves, Lupin in werewolf form might be ok to interact with.

She probably stopped them because she didn't want Lupin to chase after them, and thought it was 안전한, 안전 to just be calm.

i'm guessing either:
1. she thought he was still in his right mind
or
2. she didn't want to make any sudden movements that would startle it.

I think it's from the fact she is so smart that helps because Lupin doesn't go full wolf. he still has that human quality and she can sense that and thinks that maybe that quality could be stronger if she helped him.

Because in the film, they made a mistake.

In the books, it's made very clear that no werewolf can control himself during the full moon (unless he'd taken the wolfbane potion). Hermione would know this. She's actually the one who noticed him beginning to transform, realised the danger and shouted at the other 2 to run.