Secured within the improvised chamber created by Burton and Jama's efforts, the Entity was weakened enough to make the fight less than fully one-sided. It didn't make it that even though. Slowly but surely, Elizabeth's very essence was stripped away and consumed by the ravenous creature.
In the final struggle, she realized that her enemy was just as vulnerable as she was. Just when the Entity was about to triumph and claim her soul, she did the last thing it expected. She turned it around and possessed it. And that's when Jama spoke the words she read from the Grimorium and dispelled the Entity's presence from her body.
But not all of it. Elizabeth had willingly taken the Entity into herself, seeking to defeat it. A part of it remained within her, part of her.
To say that her ordeal had changed her was the understatement of the year. She now walked between two worlds; ours, and the other place from whence the Entities had come from.
As a walking gateway between the two realities, albeit a rather small one, she had access to the eldritch energies that powered what had become known as magic, although she had little if no idea how to harness or control them.
Her father, realizing his daughter's condition, asked Jama to help her learn the control she'd need to survive. He knew the damage was irrevocable, that his daughter would never be the same, most likely never have the normal life she should have had, but he never gave up on her.
After the final Entity incursion and Gurzorath's defeat, the Carpenter family adjusted to the new life they had. Nathan moved out of Angelus to be closer to his duties as a Knight of the Order. His wife and children were taken into the Order's greater community, albeit reluctantly in Elizabeth's case.
The Order simply couldn't really accept that Elizabeth was anything but a lost cause. Of course, it didn't help that Elizabeth had the typical teenager's attitude toward authority, and unfortunately had the ability and tendency to express it in rather elaborate ways.
It was Nathan's intercession that kept them from going so far as incarcerating her, or otherwise treating her as the enemy. Nevertheless, it was obvious she was not welcome in their ranks, so Elizabeth moved back to Angelus to take training under Jama's tutelage.
After a period spent there, Elizabeth sought additional training in a variety of mystical disciplines, traveling to what was still called "The Far East" to study them. It was during her stay in Japan that she ran afoul of the Yamaguchi-Yumi, foiling a kidnapping attempt and pretty much leaving one of their lieutenants with a bad case of face-loss.
In the last year, Elizabeth has returned to Angelus and, with Jama's permission, enrolled in the XSWAT Academy. She graduated about four months ago, and has finished her "internship" recently, in time to be assigned to the new squad.