Sierra Jonas/Cosgrove is 12 years old She has a twin sister named Tessa who is also 12. Her Older Brothers Kevin,Joe,and Nick form the band the Jonas Brothers. Sierra has always lives under her brothers shadows since she was born, been singing since she turned 1, has always done Talent Shows, Was On America's Got Talent, loves to sing and dance. Her life changed when she was 6 years old when she posted a video of her singing which caught the eyes of Music Producer L.A. Reid he sent the clip of the 6 year old to Ellen, who invited her one the show. Tessa her twin, sticks more to babysitting, and all the normal stuff, artistic, has same eye color but hair color is a lighter brown than Sierra.
Sierra when she got started changed her name to Miranda Cosgrove a stage name so no one would ever find out she was the Jonas Sister, getting her talent from them, and people saying that the only reason she was ever signed was because of her brothers, but her brothers never found out
