The girls received criticism for their 'skimpy' stage costumes on last weekend's X Factor, with some viewers deeming their outfits inappropriate for a family show.
But Coleen, whose popstar son Jake Roche, 24, is engaged to Little Mix singer Jesy Nelson, 25, defended the band on Tuesday's episode of Loose Women, saying: "I'm biased because they are talking about my future daughter in law and I won't have it! I'm very protective!"
Coleen sighed as she told the panel: "Goodness me, I mean, really? They had kind of swimsuits on; that was it. They didn't have their boobs out and weren't showing anything we haven't seen before.
"People forget with Little Mix, initially they were a very sweet girl band, very innocent, the kids that followed them were [this big]. Over the years, as you do, you develop as a woman, experience life more, get more confidence."
"Do you know what I love about them?" added Coleen. "They go out there and are so confident in themselves. For young girls with body confidence issues, they go out there, all different shapes and sizes, all confident and say, 'This is me'.
"I've seen a lot worse. Nobody screams and shouts when Beyonce comes out [half dressed]."
Coleen later agreed with one viewer who contacted the show to say Little Mix - Jesy, Perrie Edwards, Leigh-Anne Pinnock and Jade Thirlwall - are young and beautiful and if they looked like Little Mix, they would wear those sort of stage costumes as well.
Little Mix had been on X Factor's results show on Sunday night to perform new single 'Shout Out To My Ex'. They are still the only group to have won the show, triumphing under Tulisa's guidance in 2011.