Who is Angel's mother?

I played the 'snap' out of the Borderlands series and really know much about the games. But after the Pre-Sequel, I still have one big question: Who is Angel's mother? Since we only know about one girlfriend Handsome Jack (who is Angel's father) had, Mad Moxxi, I'd say that she is Angel's mother but that would not make much sense to me.

Does anyone know more about this question or has anyone encountered some ECHO recorders, that could enlighten me?

Solution 1:

According to the Borderlands Wiki, Angel's mother is unidentified.

Angel is the daughter of Hyperion programmer Handsome Jack. The identity of her mother remains unknown, but her absence from Angel's life is reportedly a result of Angel's Siren powers.

Solution 2:

Could be Steele. She was also a siren and Angel basically lured steele into opening the vault first to be killed by the destroyer. could be what Jack means by "you didn't see what she did to her mother.