Isn't the described height of Kumoro and Elaine very different?
No, but there is a WOJ shooting down the old "Murphy=Kumori" theory on those grounds, thats likely what your thinking of.
(PS--Murphy can't be Kumori, obviously. Kumori is a powerful and dangerous necromancer with the personal will to hold a knife to a wizard's throat. And more to the point, she was TALL ENOUGH to do it. If she was 5' 0" Murphy, she'd have had to be wearing freaking STILTS to hold a knife at 6' 7" Harry's throat from behind. To say nothing of the fact that Harry has touched Murphy's skin on multiple occasions and never picked up a ripple of /any/ of the aura of a practitioner, much less the utterly obvious one of a fellow heavyweight. I try to follow my own rules, guys. )