Where Love Goes by Joyce Maynard

This was a very well written book.  It is the story of two one parent families, Claire's family, which includes a son and a daughter, and Tim's which includes a daughter, Ursula.  When Tim and Claire fall in love, they try to blend their families without success.  Claire's children, especially her son, act out; so does Ursula.  The children oppose blending the families so much that it never occurs.  This was not a story with a happy ending.