I can't find a marriage either, I even tried to see whether she'd been married before and so married William under another name, but that doesn't look likely if she had a son called Finch. It could be they didn't marry.
The only thing we know about William is he was born about 1874 (from his death) and died in Sheffield. When the death notice said he had a wife and 6 children, were they all his or just the last 2? Have you got dates of the children's births?