Love Meg by C Leigh Purtill
From the jacket cover:
Fifteen-year-old Meg Shanley knows two things: first, her older sister Lucie is the only family she has. Second, Lucie will uproot her to a new town and a new school at least once a year. This time, it's Hollywood.
Alone and lonely in LA, Meg settles into a familiar routine. She scopes out New Friend candidates and determines the shortest distance between home, school and Starbucks.
Then Meg discovers a secret that turns her whole world upside down. She has a family she never knew about--an uncle and a grandmother--in Queens, New York.
Meg is convinced she can have the dream life she's always wanted. She defies Lucie and flies to Queens.
Love Meg is more than just a beach read (or Nicholas Sparks alike) that the cover seems to depict. Meg is raising herself in the ebb and flow of her older sister's love and neglect. Meg writes letters to Jennifer Aniston as her source of comfort, advice and friendship. That nearly stopped me from getting through chapter one... So the book rises above the cover and Meg's Friends obsession, but not TU caliber.
(ok maybe the Sparks and Friends comments are snarky, but literary snarky)