DD and I both read the Inheritance Games series (YA). I thought they were entertaining though the first is the best.

The Curious incident of the Dog in the Nighttime

The Golden Compass series

If fantasy is of interest at all, I'd recommend the Sharing Knife series by Lois McMaster Bujold. The protagonist is a young woman caught up in a mystical battle. She hooks up with an older man, but somehow it's not gross. And they fight evil together, each bringing their own perspective to the fight.

The same author has another good one with a strong young woman taking on big responsibilities-- The Curse of Chalion. No may-december romance in that one, but the main character is a middle-aged man who is looking out for the young woman who's crushing it at leading a rebellion.