The Saturday's singer has been accused of being a 'ringer' due to her past dance experience in the band.
But Mollie says she's really not that good at all.
"I’ve never been to stage school or had a dance class," Mollie explained. "My mum took me to a ballet class when I was three or four and the teacher said, ‘Mrs King you’re wasting your money, she has no grace.’
“Oti Mabuse had to teach me how to point my toe and I was wishing my parents had kept me in the ballet classes."
Saying she was "not a trained dancer", Mollie vowed to give her all to the show.
“I’m going to view it like a full-time job," she told The Sun newspaper. “I’m a hard worker anyway and I wouldn’t like to be going on prime-time Saturday night TV looking like a complete wally.
“Even if I look like a complete fool doing the Charleston, which at the moment is likely, if I’ve done the whole week of rehearsing then what more can I do?”
Mollie is the second member of The Saturdays to take part following Frankie Bridge who made the final in 2014.
But Mollie doesn't expect to get as far as her, saying: "I wasn’t at all surprised Frankie did well, she was always first to pick up the routines in The Saturdays — and the first one to help me.
“Myself and Una Foden were always the slowest to pick up the routine."
Mollie added: “It wasn’t anything like what I’m about to get into, so I need a partner who is willing to work hard with me. I really need to find my inner Beyonce.”
Strictly Come Dancing returns to TV next Saturday night (September 9) at 7PM on BBC One.