She is one of the cracked Twignut Triplets of Bree.  Unlike her more reserved sisters, she's highly outgoing and extroverted, always dancing around. She would seem to be in a merry musical even when she'd be alone in a dark alley, singing and spinning around, bursting out energies into every direction. 

A polite person might say, she is not the smartest of the Twignut flock. Less polite person might describe her as a simpleton. Her intelligence is at a child's level, perhaps a reason why she is surprisingly good with the children. The children, she takes care of, seem to love her, even though the parent's don't always approve her methods as a care-taker. Eony often prefers the company of the children over adults, as she considers most of the adults 'dull'.

"Adults are like stones n' children are like sweets.
 I don' eve' wanna be a stone."