The Disappearance of Lynsey Quy

On December 11, 1998, Lynsey Quy called her mother and asked if she could visit for tea. She got to her parents' home in the afternoon, and the two spent the afternoon talking about various topics, with Christmas the main focus of Lynsey's attention. Lynsey was always excited about holidays, and she was looking forward to the festive season. They discussed gifts for the kids and activities Lynsey was planning. As Lynsey left, she promised to keep in touch with her mother. That was the last time Linda saw her daughter alive.
What happened to Lynsey Quy?