The real life diaries of Rae Earl, on which the series is based, are set in the eighties instead of the nineties.
The character of Finn did not appear in the books. He was specifically written for the show.
In season 2 episode 2, Rae and her mother are in the car when the song Wannabe, by The Spice Girls, comes on the stereo. Later in the scene, they sing along to the song. The actress who plays Rae's mom, Claire Rushbook, also plays Deborah, an assistant to The Spice Girls, in the film Spice World. The film not only features The Spice Girls, but also many of their hit songs.
In episode 4 of season 1 "Don't Ever Tell Anybody Anything", Rae has a copy of "The Catcher In The Rye" on her nightstand. The closing lines of the famous coming of age novel are "Don't ever tell anybody anything. If you do, you start missing everybody."
The series is based on the first and second book of writer Rae Earl, which tells her life story as a teenager.