Mother, Where Are You? — Dorothy Woolfolk

Amateur detective Donna Rockford has her first real case...and a chance to prove to her boyfriend Pete that girls can be great at lots of things. Donna's roommate, Janet, who is adopted, has decided to find her real mother and Donna has offered to help. But Janet's past is mysteriously concealed. Someone is trying to stop their search. They're followed, they're both violently attacked. Who is Janet's mother? And why would anyone want to kill them, just because they're looking for her?