Madonna is known around the world as a famous pop star but her biggest achievement could be her family.

The 59-year-old mother-of-six took to her Instagram account to show how proud she is of her daughter Lourdes Leon.

She posted a sultry image of the 20-year-old 'lookalike' alongside a caption that read simply: 'My ray of light!'

It looked like Lourdes was on a bus or the subway when she took the photograph but it clearly made an impression with her famous mom.

Madonna shares daughter Lourdes with ex-boyfriend Carlos Leon, who she broke up with just seven months after their daughter was born.

The Like A Virgin singer is also mom to Rocco, 16, and four adopted children Mercy, 11, David, 11, Stelle, 4, and Estere, 4.

Both Madonna and Lourdes are known to share a close relationship with the pair often being photographed together.

And clearly Madonna – who shared a birthday photograph with her six children – has a special place in her heart for her eldest one.