Michael Strahan is one very proud dad, which makes the coming year so bittersweet. The GMA star has one son and three daughters and his youngest two children are growing up so fast. MORE: Michael Strahan's appearance leaves Lara Spencer in awe in latest photoMichael's twins, Isabella and Sophia, will turn 18 later this year meaning they'll likely head off to college next summer. WATCH: Michael Strahan's daughter makes runway debut The TV personality and former NFL star then faces having an empty nest as they leave the New York home they share with their dad. Michael has already expressed how hard it is to see them getting older and recently posted a snapshot when Sophia headed off to prom with her date. MORE: Michael Strahan delights fans after revealing 'mystery woman' RELATED: Good Morning America's hosts' homes are another level: Amy Robach, Robin Roberts, moreHe captioned the image: "I was not ready for this moment to see one of my babies go to prom! @sophialstrahan looked beautiful with her date Sebastian at #Prom! @michaelstrahanbrand."A post shared by michaelstrahan (@michaelstrahan)Michael Strahan's youngest children are growing up fast The 17-year-old looked beautiful, wearing a bright red dress and strappy high heels. Fans were blown away by the fact the teen was of prom age already and commented: "She’s beyond gorgeous.