What is the theme of the short story my delicate heart condition by toni cade bambara?

I suggest that in this short story character is more important than theme. However, Bamabara does suggest by the end of the story that education will be Harriet's salvation: Harriet plans to ask her teacher how she can deal with her "romantic" heart.

By the way, did you notice the several times that Harriet says, "I'm not going to lie about it," taking some pride in her strength and honesty? Yet when her mother asks her why her behavior has changed, she does lie. Thus the counselor's cruelty has wounded Harriet, but hopefully with the teacher's aid, Harriet will regain her strength of character.

Simply put, education is the cure for misunderstanding and the tool for growth ans strength.