Louise Levene 
The Following Girls [EPUB ebook] 

When Amanda Baker was 14 she found a letter written by her runaway mother to her unborn child: “Dear Jeremy“ it began “or Amanda…“. Now Baker is sixteen and sick of her lot as she moves miserably between lessons, her only solace her fifth form gang – the four Mandies – and a low-calorie diet of king-sized cigarettes. That is, until she teams up with Julia Smith, games captain and consummate game player. And so begins a passionate friendship that will threaten her future, menace her sanity and risk the betrayal of everything and everyone she holds dear.