The Perfect Secret by Jennifer Wilck

Dan Rothberg struggled after an accident killed his wife, and he nearly lost custody of his daughter. He can no longer allow himself to get attached to anything or anyone. Until he meets Hannah.
Hannah Cohen is a young executive with a meddlesome grandmother and a troubled brother. She’d like nothing better than to find her own Mr. Right, after too many Mr. Wrongs. A sexy older man with a teenage daughter was never in her plans.
As they navigate their relationship through adolescent attitudes and grandmotherly interference, they realize age is just a number and love can be right in front of them. But when the terrible truth of Dan’s former struggles is exposed, Hannah must decide if she can get past his deception and build a future with him.