This statement may be a little bit true when you consider Wangero's definition of her heritage compared to her mother's. As for right and wrong, you could argue that neither Wangero nor her mother can be completely right.
Wangero views her heritage as her African heritage. She has changed her name and her clothing from the way she was raised to reflect her research about Africa. Dee wants to gather items to display her heritage, which is the reason she wants to have the quilts for herself rather than Maggie.
Mother believes that Maggie has a better understanding of her heritage because Maggie values the family history and wants to have the quilts to remember her grandmother instead of display them as folk art, as Wangero said she would do.
You could argue that neither Wangero nor her mother truly understand their heritage. Wangero focuses too much on the larger history of her African heritage and not enough on her family history, while her mother is more concerned with the small world of the family than with learning more about the history of their culture. Can either really be right or wrong?
In "Everyday Use," Wangero doesn't understand her immediate cultural heritage. She is ashamed of being raised poor and black in the deep South. More, she does not honor the sacrifices of either her mother or her Grandma Dee (a first generation freed slave). Instead, she looks to Africa, a country where she's never been, a movement (Black nationalism) to which she's just joined, and a religious group (Nation of Islam) to which she's just converted as her new cultural heritage. These changes show how young and she is.
Mrs. Johnson, or Mama, understands where she's come from. She has no illusions about the past. She knows she is a poor, Black, uneducated Southern woman, but she wants her daughters to have it better than she did. She works tirelessly, using what little she has, to provide them with a college education, heirlooms to use for a family. She does not want all her hard work gone to waste--to be displayed on a wall and without being used.
But Dee/Wangero has taken her and her cultural heritage for granted. Wangero, as a college fad, has turned her back on the domestic life of Mrs. Johnson, Maggie, and Grandma Dee. Wangero would rather hang the quilts on the wall, like in a museum, rather than put them to everyday use. The quilts are symbolic of the cultural heritage: they are women's heirlooms, memories, stories, hopes, and frustrations. To hang them on a wall would be to turn them into fad.
Mama knows where she came from, and she has the heirlooms and language to prove it. Wangero is left, in the end, silent and titleless because she forsakes her cultural past.