NEW YORK—“Just because it’s fiction doesn’t mean it’s not real,” a character proclaims in the new musical, “Between the Lines.” Based on the book by Jodi Picoult and Samantha van Leer, this delightful, an almost-but-not-quite-ready-for-Broadway tuner is now at the Tony Kiser Theater. Delilah’s (Arielle Jacobs) 17-year-old life has been turned upside down by her parent’s…