Los Angeles - Kim Kardashian West says Caitlyn Jenner has shown her how to live "an authentic life."
The 35-year-old reality TV star posted a gushing tribute to the former Olympian on Instagram in honour of her 66th birthday on Wednesday.
Alongside of a photograph of them enjoying a pre-birthday lunch, the pregnant Keeping Up with the Kardashians star wrote: "Happy Birthday Caitlyn! Are you 66 or is Caitlyn 1? lol That was the debate at our bday lunch yesterday!
"Have the best day ever filled with lots of love & laughs! You have shown me what it's truly like to live an authentic life without caring what the world would think! I love you! (sic)"
Kim also dedicated another message to the I am Cait star, who split from her mother Kris Jenner in 2013, on her website, writing: "What a brave soul! I'm happy you are living your authentic life! You are my Woman Crush Wednesday. Happy birthday!!!"
Her younger sister Khloé, 31, also posted a message on her own website, writing: "Happy birthday to one of the most inspirational people I know. It's your first birthday, and I couldn't be more thrilled for you to celebrate it style. Get glam, girl! (sic)"
Kylie also took to Instagram with a selfie of her and Caitlyn with the caption: "Early birthday lunch with @caitlynjenner Happy birthday dad what an amazing year for you. (sic)"
Caitlyn thanked her fans for sending her their well wishes via social media by sharing a video montage of "66 special moments from this incredible year" via Flipgram.