AceShowbiz - Beyonce Knowles knew how to celebrate her youngest kids' latest milestone. To mark Sir and Rumi Carter's 4th birthday, the "Crazy in Love" hitmaker took to her personal website to offer a heartfelt tribute to the twins.

The 39-year-old R&B star shared her dedication on Sunday, June 13. "What's better than 1 gift... 2," the proud mom simply wrote on the homepage. "Happy birthday Rumi & Sir."

The birthday celebration came more than two months after Beyonce, who also shares daughter Blue Ivy with husband Jay-Z, treated her online devotees to pictures of their kids during a beach trip. One of the Instagram snaps saw her and the 9-year-old showing off their duck faces.

Another photo, meanwhile, displayed Rumi walking by the sea shore wearing a cute sundress as she sported two buns. In the last image, the 28-time Grammy-winning singer was seen standing by the water edge with her son, Sir.

Beyonce and Jay-Z welcomed their Sir and Rumi on June 13, 2017. In August the same year, the hip-hop mogul explained the inspiration behind their twins' names. "Rumi is our favorite poet, so it was for our daughter," he spilled when speaking to Rap Radar. "Sir was like, man, come out the gate. He carries himself like that. He just came out, like, Sir."

Two years later, his wife Beyonce got candid about her motherhood journey. "I think the most stressful thing for me is balancing work and life," she first divulged when speaking to Elle in December 2019.

Beyonce went on to detail, "Making sure I am present for my kids - dropping Blue off at school, taking Rumi and Sir to their activities, making time for date nights with my husband, and being home in time to have dinner with my family - all while running a company can be challenging."