His Secret Son by Jacqueline Diamond

Eight years after the fact, Dirk Peterson thought the gift of life he'd given his brother had gone unused -- until he came face-to-face with his own son and Joni, the mother of his child. With a killer on the loose, Joni turned to Dirk for protection. But the knowledge that they shared a child made their instant attraction all the more powerful -- and forbidden.

A Man of Secrets by Amanda Stevens

With her ex-husband's murdered body in her shop, Natalie Silver needed all the help she could get. However, she was surprised to find an ally in her brother-in-law, FBI agent Spencer Bishop. And as Spencer unraveled more clues, it was only a matter of time before he discovered Natalie's secret -- her six-year-old son was more than just Spencer's nephew!