"Kidzzzzzzzzz #livingforlove," Madonna wrote next to one of the images, which features a beaming Lourdes hugging her brother.
The picture also shows university student Lourdes proudly sporting a hat from the University of Michigan, where she recently enrolled as a freshman studying musical theatre and dance as she works towards her Bachelor of Fine Arts degree at the Ann Arbor Institute.
The teenager is following in her mother's footsteps as Madonna briefly studied at the institution almost 40 years ago.
Sure to enjoy her last stint of freedom before hitting the books for a year, Lourdes and her family holidayed together in Cannes in August. While Lourdes was preparing to move into a new phase of her life, Madonna also voiced her surprise at how fast her son Rocco is growing up.
"Not a baby anymore! OMG where did the time go? Happy Birthday R.R. #livingforlove" the pop superstar captioned an Instagram shot marking Rocco's 14th birthday.
Lourdes is Madonna's daughter from her relationship with Carlos Leon, while Rocco's father is British director Guy Ritchie to whom Madonna was married to between 2000 to 2008. The singer also has two adopted children, a daughter Mercy and son David.