I got this from the Wikipedia article about Thumbelina. I've never heard any of these other stories myself (except Tom Thumb), but one of them might possibly be what you're looking for:
" Sources and inspiration
“Thumbelina” is completely Andersen’s invention but takes inspiration from the traditional tale of "Tom Thumb" (both tales begin with a childless woman consulting a supernatural being about acquiring a child), the six-inch Lilliputians in Jonathan Swift’s Gulliver's Travels, Voltaire‘s short story, “Micromégas“ with its cast of huge and miniature peoples, and E.T.A. Hoffmann’s hallucinatory, erotic tale "Meister Floh" in which a tiny lady a span in height torments the hero. A tiny girl figures in Andersen‘s prose fantasy "A Journey on Foot from Holmen's Canal to the East Point of Amager" (1828) and an image similar to Andersen’s tiny being inside a flower is found in E.T.A. Hoffmann’s ’’Princess Brambilla” (1821). "
Good Luck!
" Sources and inspiration
“Thumbelina” is completely Andersen’s invention but takes inspiration from the traditional tale of "Tom Thumb" (both tales begin with a childless woman consulting a supernatural being about acquiring a child), the six-inch Lilliputians in Jonathan Swift’s Gulliver's Travels, Voltaire‘s short story, “Micromégas“ with its cast of huge and miniature peoples, and E.T.A. Hoffmann’s hallucinatory, erotic tale "Meister Floh" in which a tiny lady a span in height torments the hero. A tiny girl figures in Andersen‘s prose fantasy "A Journey on Foot from Holmen's Canal to the East Point of Amager" (1828) and an image similar to Andersen’s tiny being inside a flower is found in E.T.A. Hoffmann’s ’’Princess Brambilla” (1821). "
Good Luck!