The 32-year-old singer - who was part of Girls Aloud alongside Cheryl for 11 years - thinks the 'Crazy Stupid Love' hitmaker's huge rose-print inking is meaningless.
Sarah - who has a phoenix tattooed on her back - told The Sun newspaper's TV magazine: ''Oh God, it's ridiculous. My tattoo has meaning. I don't know what hers means.''
The blonde beauty is happy to fight Cheryl for the limelight as their shows, 'Tumble' - on which she is a contestant - and 'The X Factor', go head-to-head for Saturday night's top television ratings.
She quipped: '''X Factor'. What 'X Factor'? Who knows if I'll tune in. Let's not talk about ITV. I'm a BBC girl these days.''
Cheryl sat for three eight-hour sessions to complete her infamous tattoo, but insisted she didn't find the pain ''too bad''.
She previously said: ''I have three tattoos, this one, one on the back of my neck and the rose. The guy that did it is a proper artist, he does oil paintings, he's unbelievably talented.
''It took about three 7-8 hour sessions. It was fine, I didn't get it all done in the one go and he's really amazing at what he does so it wasn't too bad.''
The actress spoke about raising her 11 year old daughter Matilda in the wake of Heath Ledger's death eight years ago.