The Saturdays singer is so envious of the popular model's bushy brows, she tries to recreate them on a daily basis using a special sculpting mascara.
Asked about her favourite beauty product, Mollie said: ''Maybelline Brow Drama Sculpting Mascara. I love a brow - Cara Delevingne has made everyone obsessed with them. She's my brow inspiration, for sure!''
Aside from looking to other famous faces for guidance, the 26-year-old star also turns to her computer before a big fashion event to get outfit inspiration from social media sites.
Mollie enthused: ''It comes from everywhere, really. I'm not big on things like Pinterest, but I love Instagram - I think it's great for style tips.''
The bubbly blonde doesn't think being part of chart-topping girl group The Saturdays has affected the effort she puts into getting ready, revealing her biggest pet peeve is leaving the house without blow-drying her hair.
She said: ''I probably feel about the same amount of pressure as any other woman my age, we all want to look nice. I do enjoy grooming, to be honest - I always wash my hair every day. I hate it if I can't wash it, I just feel dirty.''
She added in an interview with LOOK magazine: ''We've all got very different skin types, so we never really fight over anything, but we all get quite excited about a bold statement lip - we just can't resist!''
Many ticket-holders couldn't get into the O2 Arena show on Tuesday night (September 19th) because they didn't bring photo ID to match their booking.
An album re-release, a new song and a documentary mark the singer's legacy this year.
The actor plays the titular hero in the forthcoming adaptation.