Duty Calls (Duty Series #1)

Alyson Sanders has custody of her baby niece while the child’s mother is deployed overseas. When the mother dies, her effects include a letter naming Lt. Col. Mitchlen as the father.
Not wanting her childhood to be like his, he files for custody. Neither wants a court battle, but both want custody. Things become heated as they’re drawn together, but a child’s future hangs in the balance.