The trouble was, she didn't.
She was only three inches tall, even standing on her pointy little toes. When people noticed her at all, which was hardly ever, they smiled and said how cute she looked.
But as she was flying one night, an owl did notice her. He was looking for his supper, and he thought maybe she was a tasty bat.
When he had gotten over his disappointment that she wasn't,
and when Rowena had finished screeching at him,
he gave her some advice:
The appearance of things is what matters,
when you are trying to make an impression.
If people cannot see you,
you must manifest your evilness in some other fashion.
It behooves you to improve your elocution.
The owl loved big words. In fact, this would be a very long story, if we told you everything the owl said, so we will make it short. Although Rowena hated that word!
Anyway, she could see that the owl was right. She went to Elocution School, and practiced her shrieks and cackles.
Now, when she flies through the night, and people hear her evil shrieks and cackles, and they cannot see her at all, it scares them completely out of their wits.