Article: Sandra Laing is a South African woman who was classified as Coloured by authorities during the apartheid era, due to her skin colour and hair texture, although her parents could prove at least three generations of European ancestors. At age 10, she was expelled from her all-white school. The officials' decisions based on her anomalous appearance disrupted her family and adult life. She was the subject of the 2008 biographical dramatic film Skin, which won numerous awards.

Question: How many generations of European Ancestors does Sandra Laing have?
three