Supermodel Paulina Porizkova has celebrated a major milestone in her son’s life: graduation! The 56-year-old paid tribute to her son Oliver, who is celebrating his 23rd birthday on May 23, just one day after becoming a college graduate. “This weekend, I want to send out well-wishes and congratulations to everyone whose children are taking a big step into adulthood,” she captioned her May 22 photo with Oliver and her eldest son Jonathan, 27.