I saw an interview a while back where she said it was pronounced "eh", but who knows. The thing about Adam having grown up with her...yeah, you would think he would know...but I have friends I've known for *ages* who can't pronounce my last name, and it's not even close to being that hard.
"A little humility wouldn't hurt."
--Ellie, Constantine-Hellblazer, "Dangerous Habits"