It is 12 and 3/4 inches long, made of walnut with a dragon heartstring core.
The real Bellatrix Lestrange never really broke into Gringotts. Hermione used the Polyjuice potion because she was suspicious about the way Bellatrix was behaving in the Malfoy Manor because when she asked Hermione where she had got the Godric's sword she was really worried. They thought there might be a Hocrux in Bellatrix's vault, and there was. THIS TELLS NOTHING ABOUT HER WAND!
Probably Crucio or Avada Kedvra.
Perhaps the three Lestranges: Rabastan, Rodolphus and his wife Bellatrix.
Hermione's wand is made of vine wood with a dragon heartstring core.It was stolen by Fenir Greyback and his snatchers in Harry Potter and the Deathly Hallows. After that, she stole Bellatrix Lestrange's wand and thusforth used her wand, though most unwillingly. However, it is probably likely that she asked Ollivander to make her another wand, once he was well again, of course.
Because Bellatrix's wand is broken
Barty Crouch Junior and the three Lestranges (Bellatrix, Rodolohus, Rabastan).
brownish-red
Because as a boy, tom riddle stole the cup from a "close friend", and put it in bellatrix's vault to keep it safe
She didn't have it back . She got Bellatrix Lestrange's wand instead.
Her wand is made of Walnut with a dragon heartstring core, it's 12 3/4 inches, and described as "unyielding". After Harry takes this from her, Hermione uses it until the end of the battle, when she doubt had another one made. Bellatrix then used a black wand in the Battle of Hogwarts, which she probably procured from another wandmaker or stole from somebody else.
Not known.
Not known.