There could be. Fanfiction writers love to explore different scenarios that deviate from the original story. But it's important to note that this goes against the general perception of Dumbledore's character. In the official Harry Potter series, Dumbledore is a protector, not a kidnapper. But in the world of fanfiction, anything is possible.
One common trope is the heroic rescue. Usually, her friends like Harry and Ron will come to her rescue in a daring adventure. Another is the 'damsel in distress' aspect, although Hermione is far from a typical damsel. Sometimes, the kidnapper might have some hidden motives related to her intelligence, like wanting to steal her knowledge.
In the fanfiction world, such themes are generally considered unethical. Fanfiction is often a form of creative expression within a community, and themes of kidnapping and torture go against basic moral values. It can also be disturbing to many readers.
Hermione could use her intelligence to outwit Bellatrix. She might pretend to be compliant and gradually gain Bellatrix's trust, all the while looking for an opportunity to escape. For instance, she could trick Bellatrix into thinking she has some important information that can only be retrieved in a certain location, and then make a run for it when they get there.
In 'Hermione's Ordeal', she is initially shocked but quickly composes herself. She tries to negotiate with her kidnappers, using her wits to buy time. She also attempts to analyze their motives and weaknesses, which is very Hermione - like. She doesn't just sit there and wait to be rescued; she actively tries to find a way out of the situation.
Yes, there are 'Hermione kidnapped' fanfictions. Some might explore dark themes where she is kidnapped by Death Eaters for various reasons, like using her as a hostage to get to Harry Potter. Others could be more of a plot device for a romantic rescue by a certain character, perhaps Ron or Draco in some alternate universe scenarios.
She would be terrified at first, but quickly gather her wits. Hermione is very intelligent, so she would likely start observing her surroundings, looking for any possible means of escape or a way to send a signal to her friends.
In one possible plot, Voldemort might kidnap Hermione to use her knowledge of magic against Harry. He could try to force her to reveal secrets about Dumbledore's plans or the location of certain powerful magical artifacts. Hermione, being strong - willed, would resist and try to outwit Voldemort using her intelligence.
Hermione often shows great courage in these situations. At first, she might be scared, but she soon overcomes it. She tries to gather information about her kidnappers and their plans. If they are trying to 'adopt' her, she questions their motives and tries to find out what they really want from her. She may use her intelligence to manipulate the situation to her advantage. For instance, she could pretend to go along with their adoption idea while secretly planning her escape. She also tries to stay true to her values. If her kidnappers have a different view on things like the treatment of Muggles, she will not be afraid to speak up and defend her beliefs, even in a captive situation.
Hermione would likely be very angry at first. She is a strong - willed character and being kidnapped would go against all her principles of freedom and rights. She would probably try to reason with Ron immediately, using her logical arguments to make him see how wrong his actions are.