Serena Williams' Birthday Tribute to Daughter Olympia Will Make Your Heart Swell

  In honor of daughter Alexis Olympia Ohanian Jr.'s 2nd birthday on Sunday, the superstar took to Instagram to share a candid family shot from her baby's birth. In the picture, Serena cradles the newborn while husband Alexis Ohanian kisses his wife's forehead.

"The last 2 years have been my greatest accomplishment," gushed the proud mom. And, for his part, Alexis is equally enamored. "How has it already been two years?" praised the Reddit founder. "Happy cake day @olympiaohanian. Thank you for being the greatest thing we've ever done."

This year, Serena will be celebrating Olympia from the court as she competes at the U.S. Open. Indeed, striking a balance between her personal and professional lives has been a challenge, but one the athlete has always been open and candid about.