CORONADO, Calif. (CBS 8) - One year ago the naked, bound and gagged body of Rebecca Zahau was reported to be found hanging from a balcony at the Spreckels mansion in Coronado.

Her death was ruled a suicide but her family tells News 8 they are not giving up in their efforts to get the case reopened.

"First of all, I want to thank the San Diego community for all their support and for believing Becky did not commit suicide," said Zahau's sister from her home in Missouri.

Mary Zahau spent the anniversary of her sister's death visiting her grave, remembering her laughter, and wondering if a murder investigation will ever be reopened.

"My sister died and she didn't just die, somebody took her life away," said Zahau.

During an interview via Skype aired Friday, Mary Zahau offered a plea to the California Attorney General as the office considers the family's request to launch a new investigation.

"Give it a chance with an open mind. I want them to give it a chance because I don't think my sister's case was ever investigated properly," Zahau said.

Sheriff investigators concluded Rebecca Zahau, 32, committed suicide by hanging at the mansion two days after her boyfriend's son fell off the top of the staircase. Six-year-old Max Shacknai later died from his injuries.

In an interview with Phoenix Magazine, the boy's mother, Dina Shacknai, talked for the first time about her suspicion of Rebecca Zahau and the story Zahau told police about how Max fell.

Dina Shacknai wants Max's case reopened as well.

"It's been really hard to be quiet and say nothing," Shacknai told the magazine. "It's still my job to find out what really happened to him."

Meanwhile, attorneys for the Zahau family said their own investigation showed Rebecca Zahau's death was murder.

"There was evidence of a struggle. There was blood on the body. There was a bruise on the body and a chair was overturned," said family attorney Marty Rudoy.

Rudoy told News 8 that the San Diego County Sheriff still has not returned some of Zahau's personal belongs to the family, like her camera, computer or cell phone. He said the Sheriff did make the cell phone available for an independent forensic inspection by an expert hired by the family. That forensic report still is not complete, Rudoy said.

The Coronado mansion currently is undergoing a massive remodel, which includes a new swimming pool dug into the backyard where Zahau's body was found.

The mansion's owner, Arizona millionaire Jonah Shacknai, 55, purchased a beachside vacation home last October in Del Mar for $3.3 million under the company Seafare Holdings LLC, according to real estate records.

Mary Zahau remains painfully aware what both families are going through.

"I can't imagine what they go through either," Zahau said. "Everybody goes through pain and losses in a different way, so I hope they find peace in some way also."

Monday morning in Phoenix, Dina Shacknai will hold a news conference to announce the formation of a foundation in Max's name called Maxie's House.

The organization will push to require a "safety plan" for children of divorced parents.