College friends Mikayla Stern-Ellis, 19, and Emily Nappi, 18, already had plenty in common when they met before heading to college at Tulane University — from their shared plans to perform in “The Vagina Monologues” at school to their long dark curls to their eerily similar shopping habits. They were stunned to discover, though, something else they shared: an anonymous Colombian sperm donor for a biological father. When they found out they were half-sisters, they were delighted, if shocked. “It was mind-blowing,” Mikayla recalled to the “Today” show. “I freaked out,” Emily said. “I started running around the house screaming and telling everybody.” The teens say they've become much closer since making the discovery, and their families have met. “It's just really, really cool to gain more family,” Mikayla told Matt Lauer.
