A Playboy model took her own life and that of her seven-year-old son.

On Friday morning former model Stephanie Adams took her own life and that of her seven-year-old son’s.

The “terrible” news of the pair’s death shocked friends, family, authorities and onlookers. But with no doubt, the hardest hit was her estranged husband, Charles Nicolai, who is now grieving his son, Vincent, and most likely asking himself the same question as everyone else: what made her do it?

A custody battle, law suits and what may have been the last straw

No one but Stephanie knows what was going through her mind in the moments before she took her own life alongside her son’s, whom she was clutching, in New York City about 8.15am local time. It is not yet publicly known whether she left a note.

Friends have claimed she “wasn’t depressed”, one man telling the New York Post when he spoke to the 47-year-old about a month ago that she was “happy”.

“The child — I can’t imagine she would do that. She was so close to that child, she wouldn’t even let the child go to school,” the close friend said, referring to Vincent’s home-schooling.

“People have these lives you don’t even know about. I didn’t see suicide [coming].”

The friend did, however, give an insight into her life in the week of Stephanie's death, explaining the former Playboy Playmate had experienced a setback in her and her ex-husband's battle for custody of their son.

In Manhattan Supreme Court on Wednesday, just two days before her death, Stephanie was denied permission to take Vincent for a month-long holiday to Spain, where her boyfriend lives.

Charles, a New York chiropractor, successfully fought against the plans in court, with a judge ordering her to hand in her son's passport as an extra measure.

The Post reporter Richard Johnson had a short conversation with Stephanie on Thursday where she seemed "distraught".

"All I want to do is take my son and get away from this nightmare for a few days. But they won’t let me."

The self-help book author's unsuccessful bid came after she filed for divorce from her husband in November last year. Since then she'd been seeking child support from him.

But the court appearances over her divorce and custody arrangements were taking their toll on Stephanie, her friend claimed, saying she owed money to lawyers.

It was not the first legal fight she'd been in court over. In 2012 the beauty business owner was awarded US$1.2 million, which the New York Police department was forced to pay, over a 2006 incident where a police officer used excessive force on her, falsely claiming she had pointed a gun at him.

Just a year later, she and her husband were on the other side of a suit. A former massage therapist in the chiropractor's office claimed she was fired because Stephanie thought she was "too cute" was jealous.

While the initial suit was dismissed, the woman had filed another one on different grounds that has not been settled.

And yet we can't know if that too was playing on her mind at the time of her death. Just like we can't know what drove her to commit such a despicable act as taking her own son's life.

We can't know for sure what was playing on her mind at the time of her death, nor what drove her to commit such a despicable act as taking her own son's life.

If you would like support or information regarding suicide prevention you can always call Lifeline on 13 11 14 or the Suicide Call Back Service 1300 659 467.