This recommendation comes from Summer Brennan. Check out her website here, follow her on twitter @summerbrennan, and read her book, The Oyster War.
The Mystery of Mercy Close (2012) by Marian Keyes
"A compelling tale of mystery, romance, and the irrepressible Walsh
family from the internationally bestselling author Marian Keyes. Helen
Walsh doesn’t believe in fear—it’s just something men invented to get
all the money—and yet she’s sinking. Her private investigator business
has dried up, her flat has been repossessed, and now some old demons are
resurfacing. Chief among them is her charming but dodgy ex-boyfriend
Jay Parker, who offers Helen a lucrative missing-persons case. Wayne
Diffney from boyband Laddz vanished from his house in Mercy Close—and
the Laddz have a sellout comeback gig in five days. Helen has a new
boyfriend, but Jay’s reappearance proves unsettling. Playing by her own
rules, Helen is drawn into a dark and glamorous world, where her own
worst enemy is her own head and where increasingly the only person she
feels connected to is Wayne, a man she has never even met."