A lot of those Google results look like they are indexing pages that linked to threads with Spinster Sisters in the title in the right side bar, rather than necessarily being threads that mentioned Spinster Sisters themselves. Quite a few of them, especially after the first few have:
Discussions You Might Also Like... Spinster Sisters in Santa Rosa (4 replies).
Spinster Sisters in Santa Rosa (6 replies).
as part of the highlighted text in the Google results, and those bits are from the sidebar, not the thread. The on-site search results are only returning results based on the thread.