I lost Serana!

After Vilkas or his brother Frakas, or whatever his name is, forced himself up on me so I could defeat his wolf spirit, I left Serana somewhere and now I can’t remember where I left her. Although I miss her I also enjoy the silence of Skyrim. Not that she was very chatty or anything. I wonder if I will find her again someday and if I will ask someone else to follow me around.