I'm pretty sure it's pronounced TOU-rie-el, with the initial syllable rhyming with English "cow". It doesn't mean "daughter of Mirkwood", but more generically "Daughter of the forest". taur = "forest", -iel = "daughter of" (suffix).
I'm also 98% certain that the name is formed ungrammatically. AU > O when there is a suffix, so it should be Toriel. (I obviously spent too much time on Sindarin in my freshman year of high school...)
This message was edited 8/27/2012, 7:22 PM