The Holy Spirit had brought about this pregnancy to the innocent Mary, and the angel explained the situation to Joseph. According to the messenger, Joseph would raise and protect God’s only Son. The angel even named the child—Jesus. No need for ultrasound when God sends an angel.
The assignment was given to Mary also, and I'll write about that tough commission for her later.
In Sarah and a Dad for Mandy, Sarah finds a stepdad for Mandy. Her mother didn't know who'd fathered the little girl.
I admire the men and women who faithfully love, protect and provide for children they didn't give biologically produce. They chose these children. In so doing, they quite often accept what turns out to be a challenge.