Ah, good question! WELL HAVE I GOT A TEENSY BIT OF INFO FOR YOU. 

In the IWTV script of April ‘92, 2nd draft (btw there are a number of cut lines and scenes that are in there, too), there is the mention of her name, and the child’s name:

Beyond that, no, I don’t have any other info… I also can’t recall any fanfic that honors that wife situation, bc most fanfic seems to work more from book!IWTV w/ the death of Louis’ brother Paul.

P.S. I think the wife’s name is Dianne bc HELLO Anne Rice. Die Anne? Maybe? 

P.P.S. Is Jean Marie a girl? One RPer offered Lestat’s middle names to be “Christophe Marie,” so, not sure that “Marie” needs to be a girl’s name.