A-Rod, who has been dating Lopez since early last year, posted a series of pictures of her on Instagram and wrote: "Kids, birthdays were exciting because it was all about the gifts we would be getting. A new bat, dance shoes, maybe a new CD (yes I'm old!).

"I see first-hand how that's changed for Jennifer, and how she's found joy in sharing with others. For someone who has been about giving everything she has 365 days a year — to our children, our families, the world — I hope today, we can give you all the happiness you deserve. I love you mucho Macha 13."