Guarded Heart (The Montgomerys #3‪)‬

Callie Montgomery didn't come to town to fall for her brother's best friend. Heck, three months ago, she didn't even know she HAD a brother, nevermind two -- who are just as shocked to find out she exists when she lands in Three Rivers, hoping to reconcile with the only family she can still own.

Freshly divorced, Carter Collins doesn't want to make Callie's life any more messy than it already is, but he keeps running into her like there's some kind of divine intervention happening. Now his lifelong loyalty to his best friend is challenging the desires of his heart, and in a town this small, there's not enough room to have it both ways.