Who is Lena's Mother from Delirium and what is their importance?

Lena's mother is believed to have killed herself when Lena was just a little girl. Her mother had the procedure three times, but she was never successfully cured. Lena later comes to learn that her mother did not take her own life, but rather, was imprisoned in the Crypts. Sadly, by the time Lena goes to the Crypts, her mother has escaped, and she is unable to find her.