Grace Livingston Hill 
Marcia Schuyler [EPUB ebook] 

When Marcia Schuyler’s beautiful and selfish older sister, Kate, abandons handsome David Spafford at the wedding altar, Marcia offers to take Kate’s place. Her offer is accepted, and Marcia finds herself married to a man she hardly knows.
Though David shows Marcia every kindness, she is painfully aware that he still loves her sister. A fact that strikes deep, especially since Marcia has begun to truly love her husband. Then Kate returns, and she is determined to win David back—no matter what it takes or who it hurts.
Now Marcia must fight to save her marriage and the man she loves from a desperate web of lies and deceit.