Criminal Sentence 175: How Many Houses Does This Couple Have?

From a book I read recently:

“What did Ingrid’s and her husband’s house represent for her?”

This sentence suggests that Ingrid and her husband have more than one house. If they share a house (which I believe they do), they should share the apostrophe ("Ingrid and her husband's house). They shouldn't both have an apostrophe. If they each have a house, then they would each have an apostrophe, and you would pluralize the noun:

"Ingrid's and her husband's houses"

See this post about compound possession for more info.