Stage Fright by James Howe, 1990.

A well-known actress, Michaele, who is also an old friend of Sebastian Barth’s mother, has come to town to be in a play. She’s staying with Sebastian’s family, and Sebastian has a role in the play as Michaele’s son. His friends will be working on the sets for the play, and everyone is really excited. However, Michaele herself is nervous because she hasn’t done live theater for some time. She is also struggling to get to know her nine-year-old son, who has recently come to live with her.

Then, someone begins sending her strange notes. At first, they come in the form of secret admirer notes and are accompanied by little presents. Later, the notes take a nasty turn, and Michaele becomes the victim of suspicious accidents. Someone even calls her son pretending to be his father, who lives in another state, to get him to go off on his own to meet him somewhere. Although nothing bad happens to the boy and no one comes to meet him, his sudden disappearances cause Michaele to worry that he has been kidnapped. Someone seems to be trying to frighten Michaele out of doing the play, but who is it and why?

The theme of the story is the difference between what people imagine is true and what is really true. A lot of the people in the story have unrealistic expectations of others. For instance, Michaele is impatient with her young son, who has had a troubled history of being torn between his divorced parents, who are both busy with their careers. By the end of the story, she has come to understand him better and plans to spend much more time with him.

Michaele, as a well-known actress, also attracts many admirers, most of whom have different illusions about what she is really like and what she really wants. In the end, after Sebastian reveals the culprit, Michaele decides not to let what happened stop her from going for what she knows she really wants, whether her efforts succeed or not. Michaele’s confidence is restored, and she’s looking forward to a brighter future with her son.

The book is currently available online through Internet Archive.