"Should I go get Nalia in place of Aerie or Jan?"
Nalia levels up faster than either of the other two you listed. Jan is more useful if you need a thief, as well as a mage. I would take Nalia if you have the thief covered. Jaheira is a good enough healer that you shouldn't need Whiney...err...Aerie.
[ 11-11-2001: Message edited by: Mitro Jellywadder ]