After Hohenheim left home, she often would stare out windows, as if hoping to see him walking home. Edward and Alphonse noticed this and would always try to cheer her up with their alchemy. In fact, Alphonse once said that their mother's happiness was part of the reason that they continued their research in alchemy, because it made her smile. However, they didn't realize that she smiled because it reminded her of Hohenheim and his own talents in alchemy.
Trisha succumbed to an illness during an outbreak and fell fatally ill. Edward knew that his mother's longing for their runaway father was only weakening her, and he thought that perhaps if she saw him again, she could be okay again. Initially, Edward was reluctant, muttering about how he didn't want his father's help, but knew that it would make her smile again. And for the both of them, terrified by her illness, it was all they could hope for.
Despite Edward and Alphonse sending letters out to all the people who they had records of writing to their father via return addresses on envelopes, Hohenheim never came.
On Trisha's deathbed, she told Edward and Alphonse of some money that she had stashed away (which part, if not all of, was used for payments for Edward's automail) and told the boys to take care of themselves with it. Edward tried to reassure her that they'd use it together, which led to Trisha asking if Ed would make a wreath of flowers for her, surprising him. She says that Hohenheim used to always make them for her before she slips away, her hand falling slack in Edward's hands. (2003 anime only.)
 Trisha's gravestone.
Some time after this, the grief-stricken brothers performed the fateful Human Transmutation that set the events of the series in motion. In return, the Elrics are given a mutilated mass of organs and body parts somewhat resembling the late woman's corpse before it quickly dies. The resulting remains are buried by Pinako Rockbell, who goes back to the Elric house while Ed and Al stayed with her and Winry.
In vol. 11, Hohenheim speaks to Pinako about the remains, asking if anything of it looked like Trisha, such as hair or eye color. Edward, who was eavesdropping around the corner, freezes and looks horrified as he listens. The next day, after Hohenheim has left, Edward asks Pinako if she'll show him where she buried the remains and help him uncover them. The excavation seems to cause Edward great pain, as he frequently pauses to regain his breath or vomit between digging. When they unearth the remains, Edward discovers that it wasn't their mother that they had "resurrected" that night because of the hair color and bone structure.
In the first anime series, the remains of the failed human transmutation that was Trisha takes on a larger role. After the brothers rush away from the scene looking for help, the deformed, living mass that was accidentally created manages to crawl away. Patiently waiting not far from the house was Dante, who fed it the Red Stones necessary to give it a human form. The Homunculus Sloth is thus created, taking the appearance of Trisha Elric.
In the second anime, Trisha's childhood is shown through one of Hohenheim's memories, in which he passes out from alcohol and dreams of the people he's met in the past during Episode 27 (Interlude Party). Hohenheim appears to be quite glum at a lively social gathering. He sits on an isolated log nearby, while the other Amestrians all around are dancing or feasting around the bonfire. A young Pinako starts chatting with Hohenheim, before Trisha walks up to them as a little girl. Trisha appeared to fancy Hohenheim despite their age difference at the time, as she held out her hand and asked for a dance. To her dismay however, Hohenheim declined out of his low-spiritedness. She was unsatisfied, but accepted the rejection all the same. Hohenheim and Trisha eventually fall in love as she grows older. At the end of the episode, Trisha, still fairly young, holds his hands and optimistically tells Hohenheim, "We can change!". Her hopeful perspective and gentle nature that day was perhaps the beginning of her boundless relationship with Hohenheim.
 Trisha as a child. In the Fullmetal Alchemist novels, she is briefly mentioned occasionally in the form of Edward or Alphonse's memories of their childhood or home life. In The Ties that Bind, Edward and Alphonse are both reminded of Trisha in the form of Shelley, the foster mother of a young Ishbalan boy they meet in Lambsear. While living with Shelley and the little boy, Kip, Edward and Alphonse slowly learn about what is really going on with Luon, Shelley's husband and Kip's foster father. During a private talk with Shelley, Edward grows sad and frustrated at how much Shelley's predicament reminds him of Trisha's, waiting and yearning for her husband to come home again. He remembers that Trisha used to look at a picture of their family together and smile sadly, and that once when he asked if his father was coming back, she merely smiled and said "It can't be helped," which is exactly what Shelley says when Ed asks when Luon is coming back. Angry at the situation Luon's put this family into and obviously still extremely bitter about Hohenheim doing the same, he tells Shelley that the next time she sees Luon, she should "sock him one in the jaw". Later, it is stated that if Edward had seen Hohenheim again, he would do just that, but if his mother had been alive then and he had seen her smile, all would have been forgiven.
- Pinako was midwife for both of Trisha's sons, Edward and Alphonse.
- It has never been revealed exactly what illness Trisha died from, aside from a vague, passing mention.
- With how old Trisha was when she died and how old Edward and Alphonse were at the time, she was probaby 21 or 22 when she first gave birth to Ed, and 22 or 23 when she gave birth to Al (manga and 2009 anime).