The Mirror Mirror actress-turned-author sent a copy of her book, "Unfiltered: No Shame, No Regrets, Just Me," to the former FLOTUS on a whim.
Readers were impressed with the 28-year-old's candor expressed in her book containing intimate, autobiographical stories - including troubled relationships, eating disorders, and an open letter forgiving her absent father, Phil Collins.
When Obama's sweet, unexpected thank you note dated April 3 arrived, the ecstatic Collins shared a video with her followers on Instagram, saying, "I just received a letter in the mail, which put me in a deep state of shock" and "Best way to start off my week!"
"Dear Lily: I am writing to thank you for the copy of your new book," Obama wrote in a personalized letter. "The gift was such a nice gesture and I look forward to sharing it with my daughters."
Find out what else Michelle had to say about Collins' book on the next page.