It's been said before that some of the names in the series seem to have Biblical connotations. Looking at the Wiki list you've got Michael and Cross, Angel, Saul, Simon, Mary, James, Tommy (Thomas) and Jakob . According to a couple of baby name sites: Kalani means heaven or chief; Datu means either chief or is a variant of David and Durai just means chief (ever read 10 Little Indians?). Finally, Scratch is a nickname of the devil and ink could carry "dark" connotations as well.

So

If Lizzie's name is Elizabeth, and she's vomiting because she's pregnant, does that mean someone is going to give birth to a Messiah figure? There was a Mary, but she pretty much seems like toast at this point.

BTW
Tanya supposedly means:
  • Russian--Fairy Princess
  • Sanskrit--daughter
  • Egyptian--second
  • Aramaic--It was taught
  • Malay--ask