Dannielynn Birkhead asks about Anna Nicole Smith's death

Dannielynn Birkhead, the six-year-old daughter of the late Anna Nicole Smith and photographer Larry Birkhead is beginning to ask questions about the death of her famous mother.

In a recent "Good Morning America" appearance, Birkhead -- now 39 -- talked about a trip to the Bahamas where Smith is buried next to her son Daniel.

"[Dannielynn] said, 'Why did mommy die?'" Larry said. "And I said 'You know, the doctors couldn't fix her. But if you're good ... you'll get to see her someday.'"

Dannielynn was at the center of a maelstrom when her mother died of a drug overdose in 2007. Smith's lawyer/companion Howard K. Stern was listed as Dannielynn's father, but Birkhead came forward -- along with Zsa Zsa Gabor's husband -- to claim paternity, too. A DNA test later proved Birkhead was in fact Dannielynn's biological father.

Birkhead says Dannielynn made a Mothers Day card at school, but told Birkhead to "give it to your new wife" if and when he lands one.