She told BBC Breakfast: “I think it gives a wider message that my past and the way I look is irrelevant.
“That’s something I’m really proud of.”
And she let slip that she had a dream dancer partner, confessing: “I would like to be partnered with Giovanni. Giovanni, if you’re watching, I’m coming for you!”
Former Steps star Faye Tozer, 42, and Red Dwarf’s Danny John-Jules, 57, were later revealed as two more contestants for the dance competition.
Faye told last night’s One Show she was “a pretty good dancer” but had no experience of ballroom.
Meanwhile, Danny cringed when presenters showed footage of him as a backing dancer on Wham’s Edge Of Heaven video from 1986.
Former model Katie was left blind in one eye and suffered severe burns to her face after she was attacked with sulphuric acid by ex-boyfriend Danny Lynch and an accomplice in 2008.
The pair were jailed for life.
Katie, who also works as an inspirational speaker and charity campaigner, rose to fame after bravely waiving her anonymity to raise awareness of burns victims.
She admitted she is nervous about her stint, saying: “For me it’s really out of my comfort zone and it’s not something I’ve ever done before.
“Dance-wise, I went to a musical on Thursday, and my friend noted that I wasn’t even clapping in time. So in terms of rhythm…
“I’ve been watching lots of old footage to try to get some tips but sometimes that just makes you more nervous.”
The mum of two added that the ferocious judging panel of Shirley Ballas, Bruno Tonioli, Darcey Bussell and Craig Revel Horwood is particularly daunting.
She said: “I don’t want to cry. The judges can be quite scary. I’ve developed a thick skin… hopefully I’ll be fine.”
Strictly has a launch show on BBC One next month, with the full series returning later in the autumn.