I've been thinking of the very same thing myself. There has to be a connection of some sort. I wonder how come
Isabel became such a popular name from early on? People surely must've made the association to the wicked
Jezebel.
They say that
Isabel comes from Italian and is a variant of
Elisabeth (Elisabella ->
Isabella). Then again, isn't the "bel" in
Jezebel somehow related to the "bel" in Belzebub?