Originally Published: 14 JUN 21 10:01 ET

Updated: 14 JUN 21 10:31 ET

By Marianne Garvey, CNN

(CNN) -- Beyoncé celebrated her twins' birthday with a loving tribute on her website.

The superstar singer posted a message on her website Sunday for Rumi and Sir Carter, 4, writing, "What's better than 1 gift... 2," Bey wrote on the homepage. "Happy birthday Rumi & Sir."

Bey and her husband Jay-Z welcomed daughter, Rumi, and son, Sir, on June 13, 2017. The two also share daughter Blue Ivy, 9.

In her 2019 Netflix documentary "Homecoming," Beyoncé revealed the twins were a difficult pregnancy due to complications from preeclampsia.

She also said she was trying to figure out how to balance motherhood with her career.

"I'm just trying to figure out how to balance being the mother of a 6-year-old and twins that need me and giving myself creativity," she said, adding, Physically, it was a lot to juggle. It's like, before I could rehearse 15 hours straight. I have children, I have a husband, I have to take care of my body."

She became the most-awarded female artist with her best R&B performance for "Black Parade" at the Grammy Awards this year.