The actress is calling on fans to take a selfie wearing their favourite products, share the picture on the brand's Facebook wall with the hashtag #FaceofFlower and give a reason why they should win.
Five winners will win a Flower makeover and walk the red carpet of Drew's upcoming movie Blended.
After launching, Drew's beauty line quickly developed a cult following thanks to its high quality products at purse-friendly prices.
At the spring launch of the line earlier this week, Drew revealed her bridal beauty tips.
"That day is so surreal and important and long-lasting for people, I think the biggest mistake you can make is to overdo it," Drew said at the New York event.
"Look like yourself on your wedding day — don't go with crazy spiral curls and some heavy foundation and look back at that picture and be like, 'Whoa, that doesn't look like me,'" added Drew. "It should be you but the most enhanced, beautiful, natural version of yourself."
The 39-year-old star, who is known for her trademark bright red lipstick, recalled her own natural bridal look for her wedding to art consultant Will Kopelman in 2012.
"I tried to do a dark lip on my own wedding day , and I just wasn't feeling it," said Drew. "I went very natural. It took me ten minutes to do my hair and I wore very little makeup, and I'm glad I did. I'm all for bold, but I just find that's not the day for it.
"I appreciate some women who are like, 'I really want to change my hair colour for that day,' but it's not the time to play around.
"If you are thinking of doing something bold like a nail, pick a shade that has powders and greys and neutrals in it so it tones down the 'cuckoo factor.' I think wedding days and 'cuckoo factor' are not a good combination."
As a child star most famous for her young role in E.T. the Extra-Terrestrial, Drew has grown up surrounded by hair and makeup teams and attributed this to the eventual launch of her cosmetics line.
"The reason I have created this makeup line is because I have grown up in a make-up chair," she wrote on the brand's website. "I loved watching women in this aspirational environment. But it was and always will be important to me to send messages of empowerment."