Dear Miss Snark,
You and many other people have said that in the query letter one should list any contacts that might help sell the book. I really only have one. My wife is a children's librarian for a major system and writes reviews occasionally in their journal. Many children's books don't get reviewed otherwise. I feel funny about mentioning this and given that the novel I am revising (one more time) is SciFi, I am not sure if the connection will be of any use in selling the book.
Would I just look weird if I mention it? Would I be stupid if I didn't?
You won't look weird, but you will look like you don't have a clue how publishing works. First, you don't need to mention any contacts who will help "sell the book" in your query letter unless you are Oprah or Oprah is your love slave. Even if you are married to someone who is the booker/selector of topics on a major radio/tv/newspaper you are at a disadvantage cause spousal units don't get to pick their spouse's stuff (unless of course this is poetry..but that's a separate scandal).
What can come in handy is if you are known to bookstores (cause you've had a successful book) or Sessalee Henslee thinks you're the bee's knees. That's the kind of connection that will be of interest.
Telling a science fiction editor that your wife reviews children's books for the library...well, that's like telling Miss Snark New Jersey is beautiful place to live. It may be true, but she's deeply puzzled why you think she needs to know.