This is Fern the book character for Fern the movie character, see Fern.

Fern is a dusting-talent fairy and a minor character who appears in a few books. She is usally seen wearing a pale blue and yellow dress and hat with brown hair and blue eyes.
Fern Dusting Talent

In the books

In A Masterpiece for Bess, she requests a portrait of herself from Bess. She seems to have a compulsive dusting disorder, for she can't resist dusting everything in Bess's studio when she is supposed to be posing for the portrait.

She is seen briefly in Four Clues for Rani, standing next to Spinner who might've been her partner for the Fairy Treasure Hunt.