Take. Her. Class.
Besides a seriously cool person and a total sweetheart, Mia is an excellent writing teacher. Under her, my writing improved more substantially than it did with any other professor I've had at Columbia. This, in part, is a result of her toughness. She will scrutinise bad prose. Yet, she is able to do so with such wit, sweetness, and intelligence that you never take it personally. In this way, she also sets a great tone for the whole class: we are smart kids challenging ourselves and each other, but we have a lot of fun with it.
The readings Mia assigns are stellar, and you have a lot of flexibility to write about whatever you want for your essays. I had no prior interest to Gender and Sexuality before taking her class and still found it accessible, exciting, and interesting. (On this point, she also allows for a lot of other identity explorations like race and class if gender and sexuality isn't your area.)
Her grading is somewhat harsh but you can definitely get an A if you give her your best. (I did, despite a lot of procrastination and skipping some readings.) Even if you don't, though, you will learn a lot from her.