She is typically found in the dirt and isn't familiar with the surface world. As she emerges in Abby's fairy garden, she is amazed at all the sights she sees. She learns the term for her place of residence - a home - and is taken with the homes around the street, especially a nearby green one (Hooper's Store). When she learns it's not actually a house, she sets out find a home that suits her. Inspired by a book of Abby's, she constructs several types of houses, but none of which feel like home. When her family (her mom, dad, brother and Aunt Sticky) comes looking for her, she discovers that it's a family that makes a house feel like home. She rejoins the family as they submerge back into the mud and Abby gives the homes Frankie had built to her regular, garden insects.
Her name is a reference to famous architect Frank Lloyd Wright.