Olivia AriahadiDaughter of Ari and Bethany AriahadiBorn at PeaceHealth Southwest Medical Center’s Family Birth Center at 9:50 p.m. SaturdayMya Rae BradfordDaughter of Catlin Larsen and Nadir BradfordBorn at PeaceHealth Southwest Medical Center’s Family Birth Center at 12:23 a.m. SundayThey’re tiny and beautiful girls, both with black hair, swaddled in hospital blankets and sleeping peacefully in mother’s arms. Their dads watch from a sofa near the window, and when they go home from the hospital Monday, they’ll have a chance to meet their siblings.But there’s a major difference between Olivia Ariahadi and Mya Rae Bradford. Olivia, you see, has a year on the girl down the hall at PeaceHealth Southwest Medical Center’s Family Birth Center. Born at 9:50 p.m. on New Year’s Eve, she was the last baby of 2011. Mya Rae entered the world at 12:23 a.m., apparently the first baby to arrive at any Portland-area hospital in 2012. (The first metro-area baby that will have a 2012 Oregon birth certificate arrived at 12:27 a.m. in Beaverton).Not that Olivia was in any mood to reflect on 2011 as she slept through her first media interview at about 9 a.m. Sunday. But her parents, Ari and Bethany Ariahadi, couldn’t be more pleased. Or perhaps surprised.“We weren’t trying, for the record,” said Bethany Ariahadi. With a due date of Jan. 4, the couple, who live “just down the street” from the medical center, were expecting a 2012 arrival. But when Bethany went into laborabout suppertime, they knew it wasn’t to be.The Ariahadis coincidentally chose one of 2011’s most popular baby names when they named their new daughter Olivia Joy. According to the state Department of Health, which registers birth certificates, Olivia was the state’s second-most-popular name for girls in 2010 (the latest year available) and fourth nationally.