Josef Fritzl's wife ?

I have heard almost nothing about Josef Fritzl's wife, other than that she raised three of her husband's children by their daughter. What in the world was she doing? Did she ever know her daughter was held captive in their basement? Didn't she ever question where her daughter was? Which children did she think she was taking care of? Certainly not her own daughter's kids by her own husband? Will she be prosecuted for her complicity in this huge tragedy?