Kingsolver's target audience is people who feel displaced and rejected by society.
We can arrive at this answer because:
Kingsolver tells of her experience of being rejected and isolated from the society.
She shows that this happened to her because she couldn't fit the fashion standard that society wanted,
For Kingsolver, the more she tried to meet this pattern and lessen the rejection she felt, the more unhappy and lonely she felt.
For this reason, she tells readers that they should not change who they are to be accepted, as this will not make them happy. They must be true to who they are and not force random changes.
It is important to emphasize that the target audience is the type of audience that the author wants to reach.