The Sea Wasp (Ryk E. Spoor)

I'm with you, though maybe not quite to the same degree.

There's a massive problem with the hypothetical as posed-- if you assume a "classical" vampire, turning requires death & burial; there's no "suddenly", there's no "no one else knows", etc. However, once you posit a nonclassical vampire (and the "crosses & religious symbols don't affect her" also moves the situation in that direction), then more information is required to outline the situation. Otherwise, it's an unfair, loaded question that's nearly on the level of "When did you stop beating your wife?"

Also, I've read both "I Am Legend" and "Interview with the Vampire", and so have ample "primary" evidence, as it were, for there being multiple acceptible ways of handling the potential for child vampires that are entirely dependent on the precise nature of the situation.