The Chase star Jenny had performed for Simon Cowell, Nicole Scherzinger and Louis Walsh in LA for this year's new series.
Saturday night saw the contestants in the live shows confirmed with Jenny sent home in a result that caused outrage with fans.
"I came home, cried a little bit, ate quite a lot of ice-cream," Jenny admitted this week.
However the viewer backlash prompted a rethink, with Simon calling Jenny to invite her back to compete in the live shows.
She told ITV's This Morning: "I got a phone call after what felt like the longest time. I got a call from Simon inviting me to come back."
Jenny continued: "I was not expecting that level of support from the public. After my first audition, the flood of comments I got on social media was overwhelming.
"It was so uplifting and so wonderful. I have to say thank you to people who took the time to write in and make their feelings known. That wave of affection and admiration is enough to lift anybody."
Jenny - who auditioned with Queen's Somebody To Love - will be mentored by Nicole.
She said: "Jenny was just brilliant at her audition in LA. That voice of hers is one of a kind, and she's an amazing person to get to know.
"So it was such a tough decision to make. After a lot of discussion we all agreed we had to put her through. The Overs are gonna smash it this year!"
The X Factor: Celebrity live shows will begin this weekend from Saturday, October 26 at 8:20PM on ITV.
Each week the celebrities will sing live for both the judges and viewer votes as they compete to win the prize of a record deal.
You can vote for your favourite via The X Factor app and watch episodes online and catch up via the ITV Hub.