Well, considering how she dealt with
Sauron in PJ's "The
Hobbit",
Glaurung should be a piece of cake.
I mean, Glaurung causes most of his mischief through hypnosis.
Now with
Galadriel, he bites of
much more than he can chew -
she hypnotizes
him!
Has him run up to the edge of some 1,000-foot cliff (I'm sure there were some in or around
Beleriand), jump off flapping his front legs yelling "I can fly!"
SPLAT!
And there's a nice tie-in: when
Morgoth gets the news, he mutters "I
knew that design had a weakness." It gives him the idea for
Ancalagon & Co.!
Nice ironic twist to that, don't you think?