Tjorven is derived from "tjorva", dialectal for being mischievous, not obeying. Skrållan is probably derived from "skrålla", an old dialectal word for "wrinkled" as in having wrinkled clothes after playing. Pippi has been used, but only as a middle name. Madicken is called Mardie in the U.K., Meg in the U.S. and Madita in Spanish-speaking countries. Ronja is derived from a place name in northern Sweden, "Juronjaure", but I don't know what it means.
I wish I were as crazy as people say I am ~ Loesje