Though her dad wasn't often around, the Bachelor beauty watched her older sister live with schizophrenia and her mum grapple with addiction.
It left Brooke with the responsibility of guiding her younger brothers through their childhoods and teen years.
"My youngest brother is now 18, he is now a grown adult, and I've released myself of that pressure of making sure that he's okay," she said on the podcast.
"I've been a mother since I was about nine years old practically. And I think a lot of people don't know that."
It's not the first time Brooke has opened up about her history, previously addressing the poverty and addiction that shaped her earliest years in her 2019 TED Talk, How Do You Introduce Yourself?.
"Growing up we moved around quite a bit. I didn't understand the reasons why but what I do remember is that I missed out on a huge amount of school," the reality star and youth worker explained.
"My mum's addiction to drugs was quite volatile and some times I remember getting really good and some times I remember getting really bad. It had gotten so bad that we were once removed from school and put straight into a foster home without her knowledge," she said, adding that this happened more than once.
Speaking to NW, Brooke said: "I figured out that the way that I lived wasn't exactly normal when my brothers and I went into foster care. We were treated well in care and that became the comparison that helped me to develop expectations."
At the age of 11, Brooke's grandmother had a stroke in her garden. Not only was Brooke the one who found her, but she also called the ambulance.
Just days after visiting her grandmother in hospital, Brooke's mum took her own life. At the wake, Brooke was sexually abused while she was sleeping.
"I don't remember how I processed that information or how I was feeling in that time, but what I do remember is I found a phone book and a house phone and I looked up my dad's name and I found a number and dialled," she confessed in her TED Talk.
When her stepmother answered the phone, Brooke asked to be picked up which her dad did 24 hours later. Leaving in the middle of the night, Brooke left home and didn't even say goodbye to her brothers.
"I felt like I'd lost everything in that moment. I lost my sense of belonging, my family, my mum and also my connection to my Aboriginality. This was when I had first ever thought of suicide."
Though Brooke went on to live with her dad and his family and developed her love of sport, her relationship with the other side of her family wasn't a good one.
"I moved with my dad but he was working away and thought that living with his wife [Brooke's step mum] would be good for me because she would be a motherly figure. So I lived with my step mum, which was complicated," she told NW in 2018.
At 15-years-old, she was kicked out of home.
"I'd had to take care of myself and I remember the same feelings I had at 11 came rushing back when I was 15 - 'Why won't I be loved? Why will I never be good enough? and why do I honestly keep bouncing from home to home?'"
But when a teacher took her in and showed belief in her, she began to not only believe in herself and go to therapy but she went on to work in the youth sector.
"My biggest passion in life is mental health, from working and growing up with a lot of drug and alcohol violence in my childhood really," she told SBS' Noongar Dandjoo.
She also told NW: "I think everything is an experience you have to try and turn negative into a positive."
"Growing up I didn't really want the life that I had, so I made it my focus to do whatever I needed to do to have a better life and to help young people in my situation."
Though years have passed, Brooke still keeps the memory alive of her mum.
In a throwback Instagram post, the Bachelor star recalled the time her mum worked hard so that each child would have at least one present under the Christmas tree.
"One of my early memories was this Christmas, my mum was alive and she didn’t have a lot of money, she tried really hard to put at least 1 present under the tree for all of us kids this Christmas. Oh and how god damn good was that pair of snorkels I got. I was just grateful for what I did get rather than what I didn’t get. But what I don’t get is what I’m wearing in this photo," she wrote in the caption.
"I know she will never hear it but I feel like she is," she wrote on Instagram in May.
"Dear mum, it’s been 14 years without today which means it’s RJ’s birthday too. He’s 17 Which means one more year til 18 which is scaring me. I promised that I would make sure he remembers you for how beautiful you were and your soft, kind soul but your fierceness if need be. I like to think that I’ve had an influence on him in some way, coz he’s now asking me to do face masks he’s so beautiful mum and I know every year without you, we learn to celebrate and take it all in for what it is. I wish you were here everyday but I know you’re there watching down on us. I wish I got to appreciate you a little more but I know you’re missed and loved everyday. Love B, T, E, RJ and Ky. X"
Brooke suffered another family tragedy in August 2021 when her sister passed away.
"I've been trying to process that on my own being stuck in a Sydney lockdown without my family, off country and by myself," she shared in an Instagram Story, adding that her friends and the Bachelorette production team worked tirelessly to get her a G2G pass so that she could mourn with her family in WA.
"I truly believe in life that when there comes good, comes bad. This felt like one of those moments, but I can’t believe the huge support I’ve had," she said.
"I feel, honestly, so grateful. I wouldn’t be coping if it wasn’t for production, my friends, my loved ones and (my dog) Cobar."
"Just to say… I know we’re all doing it pretty friggen rough with the current world climate. Though look to the sky and lift your head up. We will get through this."
Now the TV star is ready to share more than ever before after penning her memoir, Big Love.
Explaining that the book is about "reclaiming back my identity" after years of media coverage - not all of it kind - she wants to draw a clear line between who she really is and the version we see on TV screens.
"I have a lot more substance to me than just Bachelorette and roses and dating," she said.
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