Your only child (if you don’t have one, just imagine–if you have several, imagine there’s just one) is five years old, and she has been attacked by a vampire, and turned.
No one else knows about this. She sleeps during the day and can not survive in the sun. Also, crosses or religious symbols do not harm her or ward her off. She has a terrible allergic reaction to garlic. She must have blood every day, but she requires so little that you don’t have to kill anyone. It’s a bother to procure the blood, but not impossible.
However, she’ll remain five for all eternity… or until she’s staked. You must keep her condition a secret (lest she be killed) but you also know that you can’t care for her forever (because you’ll grow old and die), and she will never be able to care for herself. She can’t learn new things, can’t talk like a grownup, can’t become a criminal mastermind the way little girl vampires do on TV. She’ll be five always.
The question: Do you (and/or your spouse, if you have one) turn yourselves into vampires, too, so she will always have someone to care for her?