Reports surfaced late Monday that TV show "Dr. Phil" had made donations to the family's fund.
The show did not confirm or deny that allegation.
"We endorse the family's effort to search for closure to this terrible tragedy and will stand with them as they navigate through their grieving process," said "Dr. Phil" show spokeswoman Stacey Luchs.
But the second autopsy, Loridson warned, can never be as good as the first, because all of Zahau's internal organs have been removed and all of the major organs would have been dissected during the first autopsy.
"The pathologist who is doing the second autopsy needs all that information [from the first autopsy] and then he gathers all his additional information and combines the two and offers his report," he said.
The San Diego County Sheriff's Department has said the Zahau case will remain closed unless significant evidence emerges.
Investigating Zahau's death a second time may prove to be a long process, but one the family says they must pursue.
"It is our hope that Rebecca can be returned to her resting place with the truth of this tragedy finally confirmed and justice served," Horwath said.
The family's lawyer, Anne Bremner, did not respond to multiple interview requests from ABCNews.com.