The teachers, like Professor McGonagall, would be concerned but also take charge. She might use her magic to assess Hermione's condition and then arrange for her to be taken to the hospital wing. Other students would be a bit in shock. Some of Hermione's female friends might start crying, while the boys would look on in concern, not really knowing what to do.
Perhaps he freezes for a moment. The shock of seeing Pepper pass out might be so great that he's initially stunned. But then he quickly regains his composure and uses his scientific knowledge and resources to figure out what's wrong and how to help her.
Harry would probably be extremely worried. He'd immediately rush to her side, trying to figure out how to help. Ron, on the other hand, might be in a bit of a panic at first but then would do whatever he could to protect her while waiting for help. Hagrid might bring some of his home - made remedies, thinking they could work on her injury.
His friends might be involved in some way. They could be trying to protect him but something goes wrong and Harry ends up passing out. For instance, they might be using a spell to shield him but it backfires.
Hermione would likely react with more intellectual and introspective grief. Unlike some characters who might show their pain more physically or impulsively, Hermione would probably stand there, silently analyzing all the memories and what Harry's death means for the wizarding world. She might be thinking about the future without Harry and how to uphold his values.
Hermione would probably be furious. She's not one to take such an insult lightly. She might immediately retaliate with a scathing comeback, using her intelligence and quick wit to put Lavender in her place.
She would probably be very indignant. Hermione is a rule - follower at heart, and she would feel that she was being unjustly treated. So she would likely try to defend herself immediately, gathering evidence to prove her innocence. For example, if she was accused of cheating on an exam, she would bring out all her study notes and research materials to show that she had studied hard and didn't need to cheat.
Some students might be shocked. The Gryffindors, especially Hermione's friends, would be very surprised as Draco has been their rival for so long. They might initially be against it, but later come to accept it if they see how happy Hermione is.
His friends Ron and Hermione would likely be the first to find him. They are always by his side in most situations. They know Harry well and would notice if he was in trouble.
In fanfiction, one reason could be over - studying for her classes at Hogwarts. Hermione is known for her studious nature, and she might push herself too hard, staying up all night to master difficult spells or research complex magical theories. Another reason could be her involvement in a dangerous adventure. If she's constantly on the run from dark wizards or trying to solve a mystery, the stress and lack of proper rest could cause her to pass out from exhaustion.
Harry would be extremely worried. He'd probably rush to her side immediately and try to do whatever he can to help. He might blame himself for not being there to protect her. Ron, on the other hand, would be in a state of shock at first and then would try to use his humor to lighten the situation a bit while still being very concerned. Hagrid would be devastated. He sees Hermione as one of his students he cares about, and he'd likely bring some sort of magical creature - related remedy, thinking it could help.