More than that [gxg]

Ellie Kinsely is 16 years old and just started junior year with her best friend Eric. They have been best friends since they were kids, since their dads are best friends. Eric also has a sister, Josie. Ellie has a big crush on her but no one knows about that. Especially not Eric. But what happens if Josie is going to tutor Ellie and they'll spend more time together? Can she still hides her feelings then?