Father by Marriage — Suzanne Carey

From Daring "Detective"

Jake McKenzie's assignment was simple--find a client's lost granddaughter and bring her back. But the little girl's adoptive mother was not at all what he expected. Beautiful and trusting, Holly Yarborough hired him as a hand on' her ranch, welcomed him to her home--and soon she and her daughter unknowingly stole his heart.

To Darling Dad?

Jake's mission became a tangle of lies and desperate dreams. For even as he took Holly in his arms and longed to ask her to be his wife, Jake knew that his newfound family could be destroyed by the truth.