The Oranges takes place around Thanksgiving and Christmas so it makes sense that it's released later in the year.
Regardless of how bad her other films were received, Leighton's been consistently getting good reviews and recognized by critics (I read a few from top critics that are like, "yay her again, BUT PICK BETTER SCRIPTS GIRL"). This is a curve most actresses have to go through--some have more luck than others. Her films are getting better too. She filmed The Roommate first, then Country Strong (which was still recognized at the Oscars for its music and the cast was nice), Monte Carlo is her personal best received so far and The Oranges with its cast and Black List status seems promising to wrap up the year.
I Hate You, Dad seems like a step back because it's Adam Sandler, but it's an obvious summer blockbuster, her role is big, and if it's good enough for Susan Sarandon...