Opal is an out-going and loving young lady. She is not easily embarrassed and she has such an open air about her that she easily wins the confidence of others. The variety of friends she gains around her in Naomi are proof of this. From Ms. Franny, the librarian, to Otis, the animal-charming musician criminal, Opal demonstrates a heart and an understanding that draws people to her.
Opal is also determined. She dogs Otis constantly (excuse the pun) about a job until he is forced to give in. She dogs her father as well, demanding to know about her mother until he too gives in. She's determined to remember those things as well:
"I wanted to know those ten things inside and out. That way, if my mama ever came back, I could recognize her, and I would be able to grab her and hold on to her tight and not let her get away from me again."
Her determination makes her resent her father, believing that he gave up too early on his wife. In the end, she realizes that while determination is good, understanding when to let go is also good.
Finally, Opal is lonely. She lives in a neighborhood of adults, has no siblings, is in a new town, is missing a mother, and is alienated from her father. Winn-Dixie is so important because he helps her get past her loneliness, which allows her to gather new friends around her.