Pop star Madonna helped her teen-aged daughter Lourdes celebrate the end of her high school career with a pre-prom party recently.

The `Material Girl` hitmaker organised a garden party in New York City June 21 for the 17-year-old and her friends, prior to their school's annual dance, reports contactmusic.com.

In photographs posted on Instagram.com, Lourdes posed in a black and white polka dot dress with her friends.

A caption accompanying the image read: "Pre prom turn up! #yaaaaaassssssb**ch (sic)", while another shot shows off one of Lourdes' male classmates modelling his tuxedo, to which the "Vogue" singer added, "Strike a pose!"

The music icon took a break from serving as hostess and snapped a picture of a wine glass placed perfectly between her feet while she relaxed on the grass, and wrote, "Mama takes a rest! #graduateb**ch (sic)".

Lourdes is set to graduate from the Fiorello H. LaGuardia High School of Music & Art and Performing Arts Wednesday.