What single wish did Ruby nurture?

From the text:

"Emile's spirit was as broken as his body. It took three years before he could walk on his own. We moved away, to a place outside the city, a small flat, where our lives were spent modestly, me tending to my wounded husband and silently nurturing a single wish."

She stopped.

"What wish?" Eddie said.

"That he had never built that place."