Why did Hermione not give the Goblin Bellatrix wand?

Because Bellatrix’s wand was reported as lost at the Malfoy Manor where the trio ended up taking it away to Shell Cottage, so showing it would have immediately revealed that Hermione was only Bellatrix in disguise, as the real Bellatrix didn’t have her wand.

Why didnt Hermione Help Harry save Dobby?

In the book, it’s primarily because: Hermione didn’t disapparate with Harry and Dobby from Malfoy manner. So it’s possible she wasn’t close by them. Ron apparated with her based on the description of the scene and not knowing Dobby’s injury, he probably took her right back to Shell Cottage without thinking.

What happens when Hermione is asked to hand over her wand?

But when Hermione in Bellatrix costume is asked to hand over her wand for verification, she protests and the situation starts to get quite nervous and ultimately has to be resolved by a disguised Harry casting an Imperio curse upon the receptionist.

How did Ron and Hermione dress up as Bellatrix Lestrange?

At the beginning of Harry Potter and The Deathly Hallows: Part 2 the gang tries to break into Bellatrix Lestrange’s vault at Gringot’s using polyjuice potion to dress Hermione and Ron as Bellatrix and some other Death Eater respectively.

Do the goblins of Gringotts know that Bellatrix’s wand has been stolen?

“They know!” whispered Griphook in Harry’s ear, “They must have been warned there might be an imposter!” “Your wand will do, madam,” said the goblin. He held out a slightly trembling hand, and in a dreadful blast of realization Harry knew that the goblins of Gringotts were aware that Bellatrix’s wand had been stolen.

How does Bellatrix know Hermione is an Occlumens?

As a corollary, Bellatrix will know that Hermione is an unusually skilled witch. It’s plausible that Hermione is a capable Occlumens, who could fool Bellatrix. Given the gravity of the situation, Bellatrix may prefer to use more tried-and-tested techniques.