I have the slice of life mod and was also was invited to Sylvan Glade. And I have a husband and wife (husband is a vampire and the wife is pregnant). It was a ghost inviting them (though the invitation was worded differently from yours). The husband was invited, but I had the wife go, too. Now they are all just standing…
You should try and find a magnifying glass floating near where it wants you to fingerprint...It'll allow you to use it there. I'm having troubles with fingerprinting this one guy's house because it keeps teleporting me out. Grr. So, if anyone knows anything about that, I would appreciate some help. :)