Blue Moon Promise, Under Texas Stars Series by Colleen Coble and published by Thomas Nelson.
Lucy Marsh has lost everything but her determination to provide for her brother and sister. When she realizes her father was likely killed by an intruder who is now after her brother, she decides to accept a proxy marriage in order to get her siblings out of harm's way. But trouble follows her to Wichita, Texas, and nothing there is as she expected. Not the man she came to marry nor the family ties she'd hoped to find. Can it be true that real security is in letting go of her own strength and trusting in the One who is far stronger than she?