One Plus One by Jojo Moyes reminded me a little of the Jill Mansell's chic lit books. I thought she captured the trials and tribulations of teens well along with insights into the struggles of a single parent.
From the cover:
Suppose your life sucks. A lot. Your husband has done a vanishing act, your teenage stepson is being bullied, and your math whiz daughter has a once-in-a-lifetime opportunity that you can’t afford to pay for. That’s Jess’s life in a nutshell—until an unexpected knight in shining armor offers to rescue them. Only Jess’s knight turns out to be Geeky Ed, the obnoxious tech millionaire whose vacation home she happens to clean. But Ed has big problems of his own, and driving the dysfunctional family to the Math Olympiad feels like his first unselfish act in ages . . . maybe ever.