Justin Bieber’s not the only one in his family celebrating a major milestone. The newly engaged singer has welcomed a new baby sister! He shared a photo of his adorable sis on Thursday, Aug. 16, on Instagram, captioning it, “Meet the newest bieber, my little sister BAY BIEBER.” Bay’s mom and dad are Justin’s father, Jeremy Bieber, and his wife, Chelsey Rebelo. The couple went public with Chelsey’s pregnant in February shortly after their wedding. Congrats!
