I just completed the "corn field quest" (Named such by me since it's a little boy using strange powers to make others do his bidding, a la that one episode of Twilight Zone) in the most ecumenical way possible (brought the Circle of Magi around and had them perform the ritual so neither mother nor son died) buuuuuut my journal has it listed under both Connor and Isolde that the mother died to save the son...does this affect how the plot progresses or is it just a minor tracking glitch? Cause she's still alive ingame as far as I can tell.

It didn't alter the plot in any noticeable way, but there is one point later in the game where someone comments about the Arl not bringing his wife to some event.  Now this could just be because she's staying home to babysit, or perhaps the implication is she considered to be dead.  This is just a passing comment that you overhear so it does not change the story in any way I could tell.

Good to know, danka.