An explanation of this quote meaning?

So gradually, she pressed her teeth together and learned to hush. The spirit of the marriage left the bedroom and took to living in the parlor. It was there to shake hands whenever company came to visit, but it never went back inside the bedroom again. So she put something in there to represent the spirit like a pure Mary image in a church. The bed was no longer a daisy-field for her and Joe to play in. It was a place where she went and laid down when she was sleepy and tired.
She wasn't petal-open anymore with him. She was twenty-four and seven years married when she knew.