Let's consider the evidence:
- She (and her vampire friends) are always up at all hours of the night
- I never hear a peep during the day
- If I do see her at all, she's wearing black and running (to avoid the sunlight, I'm sure)
So if we disappear one weekend, I'm sure it will be because we will have been attacked coming home in the wee hours of the night, by our friendly neighborhood vampire and her vampire friends.