By Alexandra Whittaker
Updated Feb 06, 2018 @ 10:00 am

While the Kardashian family has been vocally supportive of Kylie Jenner and her first child—they even made appearances in her "To Our Daughter" video—one of the new mother's parents has been quiet. Caitlyn Jenner has been mum about her daughter Kylie's pregnancy and birth, that is, until Monday, when she shared a simple Instagram photo of a baby girl.

Caitlyn used a throwback photo of baby Kylie to celebrate the arrival of her new granddaughter, and it's pretty cute.

“My daughter just had a daughter. It’s amazing to be by your side through this journey," Caitlyn wrote. "She’s SO beautiful already. Can’t wait to watch her grow. Throwback to my baby, as a baby @kyliejenner."

The rest of the family seems equally supportive. Kim Kardashian West shared a post on her app on Monday that let the world know how she feels about her baby sister's new baby.

"Mommy Kylie!!! You did it!!! I'm so incredibly proud of the woman you have grown up to be and I know that you are going to be the best mom to your new baby girl!" she wrote. "Our girls are two weeks apart and I can’t wait for them to be besties! I am so proud that you do what you want to do and live your life the way you want, you will pass down all of those amazing qualities to your baby girl. You were made to be a mom! I love you!"

Kris Jenner followed suit by sharing her thoughts on social media. “God is SO good!!" she wrote. "I am so excited and thrilled to welcome another precious baby girl to our beautiful, ever growing family. We are blessed beyond belief!”

Kylie's older sisters Khloé Kardashian (who is also expecting) and Kendall Jenner also shared Kylie's video about her pregnancy, so clearly this family is behind Kylie one hundred percent.