Mother

is a character in D.Gray-man: Reverse. She is an old woman who lives in the church in a small part of town. She latered appeared during the Seed of Destruction Arc.

Appearance
She is a small old lady who carries cigarette to smoke.

Personality
She has a harsh personality but deep down she cares for people's well being. She doesn't tolerate cheating as she hits Allen when he cheats.

History
Apparently Allen Walker once indebted to her, it was revealed that she sheltered Cross and Allen after Mana's death.

The Traveling Clergyman (Reverse)
This happens just before Allen reaches the Black Order HQ. He visits Mother to find his way. Allen is taken to meet Mother by Barba and she gives him food and forces him to play poker with him. While playing, Allen tends to cheat as a force of habit but is caught by mother who is frustrated by his upbringing. Allen explains her that he needed to earn money for his travel expenses so he had to take a few bad ways. Mother then inquires Allen about Master Cross. Allen informs her that he's gone missing and he is trying to head to the Excorcist HQ and he needs coordinates. Mother agrees to help but in return of something.

At nightfall, Mother takes Allen to a cemetry near the church and shows him a woman named Riza there. She explains how Riza makes her visit everyday and if he helps Riza get back to her feet, Mother will tell him about HQ location. Mother than forces Allen into the cemetery

Later when the Broker doctor has been unmasked and tries to escape Mother arrives and  gives a surprising kick to the Doctor who loses his conciousness. Mother gives HQ location to Allen and tells him that he isn't fully prepared to be an exorcist. He has to be strong like Riza and be ready to face humans if necessary.

The Person Who Sells Souls Arc (Anime only)
This arc is an adaptation of the Reverse chapter with a few differences.

Allen and Lenalee arrive at Liverpool to meet her, who took care of Allen during his training years with General Cross, to ask her about his master's whereabouts. She gives tells them that she is worried about what is happening in the hospital and fears the earl is involved.

Seed of Destruction Arc
She was seen wondering and reminising about her time with Allen and Cross, and especially wondered if Allen had been consumed by the 14th yet. She was shocked when an exhausted Allen Walker, who was running from Apocryphos and the Order, appeared at her church.

Trivia

 * Mother appeared first in Reverse then in the anime and lastly in the manga.