In adulthood Erickson put off joining Starfleet and dedicated herself to taking care of her father after he was seriously injured in a transporter accident that confined him to a wheel chair. After her brother was apparently killed in a transporter accident in 2139 her father became obsessed with the idea that Quinn was trapped in subspace.
In 2154 her father staged a ruse to gain access to the Enterprise, telling Starfleet that he was working on the sub-quantum transporter while he actually wanted to retrieve his son from subspace. Erickson assisted her father, keeping silent about the real reason her father came aboard. While the Enterprise crew modified the transporter, Quinn - now a subspace energy signal - came aboard and accidentally killed a crewman he came in contact with. Following this Archer confronted Erickson's father and learned the real reason he and his daughter had come aboard. They allowed him to continue with the efforts to retrieve Quinn. Emory was able to retrieve Quinn, who died moments after rematerializing. For his part, Quinn's father was relieved that he no longer existed between life and death in subspace. (ENT episode: "Daedalus")
Erickson and her father returned to Earth on board the Sarajevo. Emory Erickson was incarcerated for his crimes and would eventually die in prison. Erickson herself was not criminally charged, however the incident did scuttle her attempt to join Starfleet.
By 2163 Federation physicians realized that extended use of the transporter was detrimental to living beings, causing cellular degradation due to single bit errors in the reassembly process. Erickson's friend Jonathan Archer suffered neurological damage due to his use of the transporter, while Archer's former armory officer Malcolm Reed had damage to his reproductive organs which precluded any possibility of his having children. Erickson was relieved that her father died before it was known that extended transporter usage was damaging to living organisms, knowing that he would blame himself for the injuries people who used his invention sustained. She herself refused to perform transporter research, but was still continually asked by reporters if a workaround to the damage was coming soon.
After the founding of the Federation, Erickson would often join her friend Jonathan Archer for lunch when he was on Earth. By 2164 Archer finally worked up the nerve to ask her out when the reception was held for the first Rigellian Federation councilor in Paris. (ENT - Rise of the Federation novel: Tower of Babel)