Final answer:
The irony in Dee saying she doesn't understand their heritage is that she is disconnected from it.
Step-by-step explanation:
The irony in Dee saying that she doesn't understand their heritage is that she is actually disconnected from her heritage. Throughout the story, it is evident that Dee has changed her name, taken Polaroids, and is interested in the quilt for its artistic value. However, she does not truly understand the historical and cultural significance of their heritage.