Help identify a book?

It’s driving me crazy, and I’ve tried googling the story multiple ways, with no luck.

The plot is a family saga, centering around a daughter. The book opens up with the father riding a bus back to Kentucky from somewhere in the midwest, where he’s been working as a farm laborer. It is sometime in the 1930’s. He has lost the family farm, and is moving his family to Florida where he has found work on a citrus farm. The first part of the book talks about the relationship with the land.

The daughter somehow meets and marries a rather wealthy young man from a small town in upstate New York. She struggles to find her own identity and place among strangers, separated from her family, and from her roots. I think part of the story is that she has a child with someone other than her husband, and ends up separating from him.

The part of this book that sticks with me is idea that it takes three generations to better a family’s circumstances, but only one generation to fall.

I’m sure the book is somewhere in the house. I’ve looked at the Bobbie Ann Mason, Wendell Berry and Harriette Arnow books I could find on the shelves. It’s driving me crazy that I cannot place the book.