The blonde beauty has insisted she won't quit the girl group because she would miss having her band mates there to share every experience with.
She told the Sunday Express magazine: ''I think I would have the guts to go it alone.
''But I just love doing it with the girls because, as much as you can call your mum when you get off stage, you can never explain the exact feeling.
''With the girls when you come off, you're all like, 'My God! Did you see that?' And that's something you'll never get if you're up there on your own.''
Her dedication to the band even means Mollie is having to try to balance her career with a long-distance relationship.
She is living in the UK, while her boyfriend Jordan Omley is a producer in Los Angeles.
She explained: ''We travel a lot to meet up but obviously we don't see each other every day.
''I live on Skype and FaceTime ... I do love it out there. It's such a nice lifestyle, isn't it?
''I love the people and the weather but my career is everything to me right now - and that's here.''
The movie begins filming in the UK.
The 'Sherlock' and 'Doctor Strange' star joined Gilmour onstage at the Royal Albert Hall for a rendition of the Pink Floyd classic.