Of course, it depends what you are trying to say about Dee. When you are writing a thesis statement about a literary work, it is important to consider using the title or author, a strong verb, and a position you have about what you are writing about.
In this case, a variety of thesis statements might work for you:
1. Walker's "Everyday Use" illustrates Dee's struggle for identity by juxtaposing her quest for a new identity against her family's desire for maintaining culture and heritage.
In this case, you could write a healthy first body paragraph about how Dee is venturing on her own and seeking to use the family's heirlooms for art, while your second body paragraph could express her mother and sister's urging to keep the items for everyday use.
2. Dee's character in Walker's "Everyday Use" illustrates the themes of heritage, materialism, and identity.
This simpler thesis sets the writer up to thematically explore her character throughout the storyline.