After her canonization in 1267 this miracle was attributed to Hedwig:
When the son of a prominent judge was still unable to walk at eight years of age, his mother brought the boy to the grave of St. Hedwig in her arms and was praying to St. Hedwig to heal him when, lo!, a miracle happened. In the presence of the priest who baptized him and the abbess of the monastery, the boy suddenly stood up, took an egg that lay before him and walked around the saint's grave. The abbess took other decorated eggs and threw them at the feet of the young boy, compelling him to walk further from the tomb. This miracle is said to have happened near Easter between 1274 and 1287" (p. 107, Polish Customs, Traditions, & Folklore by Sophie Hodorowicz Knab).
CLOCHE tip: Catholic Culture