CORONADO, Calif. (CBS 8) -- The identity of a mystery woman spotted at the Spreckels mansion by a passerby hours before the July 13 death of Rebecca Zahau was confirmed Wednesday, November 2.

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Nina Romano, 41, is the former sister-in-law of the mansion's owner, Jonah Shacknai. Romano's twin sister is Dina Shacknai, Jonah's ex-wife and the mother of Max Shacknai, 6, who died after falling down a staircase at the home on July 11.

"The San Diego Sheriff's Department was at the hospital speaking with Jonah Shacknai the morning of July 13th (I was at my nephew's bedside as well that morning)," Romano revealed in an email to News 8.

"I VOLUNTARILY told the detectives that I went by the mansion for a few minutes the night before at 10 p.m. but no one answered the door," Romano explained.

Records show the Northern California resident was one of the last persons to send a text message to Zahau, 32, before her bizarre death.

"I just wanted to talk to her about the accident and so I sent her a text message that just said, 'Hey, are you around? I'd like to come by.' And, I never heard from her. She never responded to me. It went nowhere because I didn't get any message back from her," Romano told News 8 during a September phone interview.

The text message was backed up by phone records obtained by News 8, which showed Romano's text was received by Zahau at 10:41 p.m. on July 12. Romano disputed that time stamp and said she sent the message closer to 9:41 p.m. on July 12.

The San Diego Medical Examiner put Zahau's time of death around 3 a.m. on July 13.

Adam Shackani, Jonah's brother, called 911 at 6:45 a.m. to report he had emerged from the mansion's guest house to find Zahau hanging from a second-story balcony. Zahau – Jonah Shacknai's girlfriend – was bound, gagged and naked at the time of her death.

Investigators believe Zahau committed suicide because she was distraught after learning Max Shacknai would not recover from his injuries, which happened while Zahau was babysitting the boy.

Zahau's sisters have said they believe she was murdered. Earlier this week, Zahau family attorney, Anne Bremner, obtained new police reports, witness interviews and transcripts in the case.

Bremner said the reports indicate Romano provided DNA and fingerprint samples to detectives. Romano confirmed as much in her email to News 8 Wednesday.

"I wanted to help the San Diego Sheriff's Department in any way that I could regarding Rebecca, so I voluntarily meet with them, gave them an interview and voluntarily gave them my DNA," wrote Romano.

Romano declined to be interviewed by News 8.

Detectives closed their investigation Sept. 2, after ruling the boy's death an accidental fall and Zahau's death a suicide by hanging.