Bellatrix realised only a week after Hermione's arrival how truly powerful the Young Woman was and it made her see the Blood status as nothing more than an excuse to hate certain people just like she once knew when she was younger. She felt herself becoming that person once more where she didn't care for blood status, she only cared for the powerful Witches and Wizards in the world. She still wanted a Wizarding World to filter the weak from the strong, she just didn't care about the blood status they held and she was working herself up to expressing this view to Voldemort and using Hermione as her example.