The 20-year-old sent her big sister a heart-shaped arrangement of white and blush pink roses.
Kim, 37, shared a video of the beautiful flowers on Snapchat exclaiming: "How beautiful are these flowers? Thank you, Kylie!"
Mum kris Jenner was one of the first to congratulate the Kardashian West's on the arrival of their daughter, who was welcomed via surrogate on January 15.
The momager sent her daughter a cake with edible pink roses, to reflect her baby's gender.
Kim and Kanye West welcomed their third child via surrogate on Monday January 15, 2018.
The Keeping Up With The Kardashians star shared the news on her website, writing:
“Kanye and I are happy to announce the arrival of our healthy, beautiful baby girl.
“We are incredibly grateful to our surrogate who made our dreams come true with the greatest gift one could give and to our wonderful doctors and nurses for their special care.”