In her autobiography, Gemma apparently says she was a bad student and almost got expelled. But Fr. Germanus says she was such a good student she won prizes in school.
The other one I noticed was the instance of her cousin touching her face. In her autobiography, Gemma says he was cruel to her and meant to pinch her on the face, but she pushed him hard. In the biography by her spiritual director, he makes it seem much more different: he says her cousin was grateful to her for retrieving some item, made a move to touch her tenderly on the cheek, but was repelled by some supernatural force and fell down.
It bugs me that there are discrepancies.