Undermine all of her previous interests and find her new and cuter hobbies.
Her new pastimes will be cuticles and talking about her roots. So it is commanded.
Do not speak to her in public until steps 1-6 have been completed, she's not ready.
She cannot become integrated into your social sphere just yet. She's still talking about those goddamn bangs in her sleep. Your work isn't done.
Give her her first pair of high heels and make her walk around in them in front of a lot of people so that when she inevitably falls, she is humbled.
She's been feeling self-assured since your friend Tom hit on her at Tina's birthday party last Saturday. It's time to knock her back down a few pegs.
Do not let her know that you're only talking to her because of a bet/dare/bribe.
...At least until after you've bought her the expensive clothes, because then she's pretty much your indentured servant for life.
Carefully and surgically remove her from her closest circle of lifelong friends and integrate her into the popular crowd where she will remain as long as you wish it.
And once she is there, she can live out the rest of her days talking to Avery and Melissa about their eyebrow shapes. At this point, she'll finally know you think she's beautiful. You've given her so much. Go you.