Who is she?

Her name is Angelina Durless but most people call her Madam Red. She is Ciel's aunt on his mother's side.

Madame Red: Baroness Angelina Durless-Barnett. Ciel's auntie to his mom's side of the family...
In a way, she's Grell's mistress... to the point that he's serving her for a purpose. But she ended up dying in Grell's hands...

She's Madam Red

That's Madam Red~
She's Ciel's Aunt

Angelina Durless

She is Ciel Phantomhive's aunt. She goes によって the name Madame Red. If あなた have seen the first series she is also a big part in a couple of episodes too.

She is Madame Red または also known as Jack the Ripper in one of the episodes.

madam red......ciel's aunt

Madam Red

She's Madam Red (or Angelena Durless) but only appears in the first few episodes.