BIOGRAPHY - Page 2
During the Mutant Massacre, Betsy helped the X-Men in every way she could. She used her telepathy to ease the pain of the wounded Morlocks and also scanned for intruders, which was how she discovered Sabretooth attacking the mansion. He nearly took her by surprise, but she fought back and led him on a wild chase through the mansion, luring him away from any of the injured people. Finally, when Logan intervened and kept Sabretooth busy, she used the distraction to slip past his psychic defenses and extract information on the mastermind behind the massacre – Mister Sinister. Betsy's performance impressed the X-Men so much that they offered her the opportunity to join the team officially. [Uncanny X-Men (1st series) #213] Her telepathy was soon needed to save a teammate; after being injured in the Massacre, Shadowcat was stuck in a phased state and slowly dissolving. Betsy kept her mind together until Mr. Fantastic and Dr. Doom found a cure for Kitty. [Fantastic Four vs. X-Men #1-4]
Shortly afterwards, the continued presence of the Marauders forced the X-Men to go underground. Unfortunately, reserve X-Man Havok stumbled in, right as the team were discussing this plan. 
In order to protect themselves, Psylocke erased the incident from his memory. However, trained by Professor Xavier, Havok's psi-shields proved to be too strong. He was having strange dreams of being attacked by the X-Men, so he went to New York again and tracked them to the Morlock tunnels. Psylocke dared not tamper with his mind a second time, fearing she might permanently damage it. The X-Men wondered what to do, as Havok knowing of their location would have endangered their plan, especially if he fell into the Marauders' hands. Going a little bit over the edge, Psylocke even suggested killing him, but the others reminded her that this would make them no better then the villains. Hearing all this, Havok felt that he was needed and fully rejoined the team, though he was suspicious of the purple-haired telepath who had violated his privacy by invading his mind. [Uncanny X-Men (1st series) #219]
Later, when the X-Men were transported to another planet and faced their heart’s desires in the Citadel of Light and Shadow, Betsy lost the last of her inner doubts regarding her status as an X-Man, since it showed her that she wished nothing more than be a warrior, capable of protecting those she cared for. [Uncanny X-Men Annual (1st series) #11]
Shortly afterwards, during the Fall of the Mutants, the X-Men battled an mystical entity known as the Adversary. The team's physical and spiritual essences were used as fuel for Forge's mystic spell that destroyed the Adversary and saved the multiverse. The X-Men, in effect, died. Roma, a prisoner of the Adversary and guardian of the multiverse, used her powers to recreate the X-Men from scratch. They decided to keep up the illusion that they were dead, in order to police mutantkind without interference. To help them in this matter, Roma rendered the X-Men present, as well as their friend Madelyne Pryor, invisible to cameras and all forms of detection equipment. [Uncanny X-Men (1st series) #225-227]
After defeating the Reavers, the X-Men took the cyborgs' Australian Outback base as their own headquarters. Soon, Psylocke thought herself to be a liability to the team in physical battles, which is why Wolverine requested an armored bodysuit for her through his contacts, providing Betsy with some sort of protection. [Uncanny X-Men (1st series) #232]
Isolated in the Australian Outback, Betsy formed a close relationship to Colossus. She even posed naked for him doing sketches. [Uncanny X-Men (1st series) #240]
Even though the team survived the Inferno conflict unscathed, shortly afterwards they lost many members. Longshot went off on a search for his inner balance, Wolverine spent more and more time as Patch in Madripoor, Rogue was sucked into the Siege Perilous and Storm was apparently killed. Tensions lay bare and old conflicts flared up again. Havok once again accused Betsy of reading his mind without being invited and her explanations that it was sometimes hard to screen other thoughts seemed insufficient to him.
Havok also was not pleased when she assumed command of the team, but he had to admit that of the few remaining X-Men she was the most capable person for the job. [Uncanny X-Men (1st series) #249]
While the last four X-Men were on a mission in the Savage Land, Betsy experienced a precognitive flash of the Reavers defeating the X-Men in Australia; most were killed and she herself turned into a Reaver too. When Gateway teleported them back to the Australian Outback without warning, Betsy knew that she had to make a quick choice, as she could already sense the cyborgs approaching. She suggested it was best to disband the team and walk through the Siege Perilous. Dazzler and Colossus were easily convinced, even though they probably would never see each other again in their new lives.
Only Havok opposed her choice, so Betsy used her telepathy on him to make him enter the mystical doorway too. Ironically, with this act, she once more violated his personal rights and actually proved his suspicions about her to be true. After the three X-Men were gone, Psylocke too escaped into the Siege right as the Reavers arrived. [Uncanny X-Men (1st series) #250-251]