"I have never cried so much in my life. I literally went through a month of life that I can't remember," Ms Van der Baan said.

Jennifer died in March at age 15. "Everyone called her Jen. She was so loved. If only she knew how much. I wish she did," her mum said.

When she hears a song that her daughter liked, the tears return.

Her hairbrush still sits on the bathroom sink.

"I can't sit in her seat on the lounge," she said.

Ms Van der Baan knew she had to do something to honour the memory of Jen.

So this Sunday, she will participate in the City2Surf in Sydney to raise money for Headspace.

She will turn 50 on the day of the event.

"I have 19 other people doing it with me - kids, grandkids, family and girls I used to play soccer with. We'll walk together as a team, with shirts made up with my daughter's picture on it."

Mother and daughter had walked the event twice before.

"I like doing it because it's always around my birthday. I was going to do it with her.

"Because she's not here, I thought I'd do it to support young people in need.

"There needs to be more awareness about youth and mental health."

She said the event "means the world to me". She hopes it will help others get the help they need.

"If I can help another child that needs it, that will make me feel a little bit better."

Jen would have been in year 10 at Callaghan College's Waratah Campus.

"She wouldn't go to school in the last couple of years. She refused to leave the house or do anything," she said.

"I tried to take her and she would walk straight back home. I don't know if she was being bullied. She didn't talk to me about stuff like that.

"All she talked about was cooking food, going for drives to the beach and her dog. She went into her shell and didn't want to talk to anyone, go anywhere or do anything in the last few months."

She tried to take her daughter to a GP.

"Every time we went, she would not get out of the car. It was traumatic."

Research shows people across the world want to break the silence surrounding suicide to reduce stigma and encourage people to speak about mental health.

Everymind, an institute dedicated to the prevention of mental ill-health and suicide, has produced guidelines for reporting on these issues.

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The guidelines state that it is helpful when the community is informed about the risk factors of suicide, "including warning signs".

"Covering suicide sensitively and accurately can challenge public misconceptions and myths, increase community awareness and encourage discussion and prevention activities."

Beyond Blue said suicidal warning signs include social withdrawal, a persistent drop in mood, disinterest in maintaining personal hygiene or appearance, uncharacteristically reckless behaviour, rapid weight changes, being distracted, anger, insomnia and giving away sentimental or expensive possessions.

Other signs are hopelessness, failing to see a future, believing they are a burden to others, saying they feel worthless or alone and talking about their death or wanting to die.

"If you're having suicidal thoughts, talking about how you feel can be incredibly helpful and a number of people can support you, depending on what you're looking for," Beyond Blue states.

"At first you might share your thoughts with someone you trust and feel comfortable with - this could be someone in your family, a friend, a teacher, doctor or other health professional.

"Remember that thoughts of suicide are just thoughts; you don't have to act on them. These thoughts might only last a few minutes; you might feel differently in a few hours."

Orygen, which researches youth mental health, said about a third of deaths among people aged 15 to 25 are attributed to suicide.

Dr Jo Robinson, of Orygen, said a national youth suicide prevention plan is "long overdue".

Ms Van der Baan believes raising awareness of mental health is vital.

"Kids need to talk about it," she said, adding that the issue should be taught from primary school age.

She's had a lot of support from her family and workplace to help her deal with the emptiness she feels.

"It's like a big chunk has been ripped away," she said.

"She was my youngest."