According to what i read, the person that you are referring to is The Late Lark Previn, the adopted daughter of Mia Farrow & her then husband Andre Previn. Lark Previn died on Christmas day 2008 at the age of 35. although her cause of death was not disclosed, Lark Previn was reportedly being treated for Aids- related pneumonia & the only information disclosed was that Previn was ill for about a decade. however, i recall reading several years ago that Lark had allegedly contracted the aids virus from her husband. also, i read that when she became too ill to care for her children, Mia Farrow helped to care for them until she was well enough to resume caring for them.