This week she did a 7km training walk ahead of her next challenge, the Hawke's Bay marathon 10km event.
Her illness led to Ms Barrett having both legs amputated below the knee, and also losing both hands.
She was determined her situation would not stop her living her dreams.
``It's nice to challenge myself, and also to show other people what is possible, and that's why I do what I do sometimes.
``I had three choices when I woke up and was faced with the fact that I was going to lose my legs and possibly lose my hands and fingers - give up, give in or give it all you've got, and I decided to give it all I've got.''
A keynote speaker at this year's Amputees Federation of New Zealand conference, being held in Dunedin this weekend, Ms Barrett will talk about resilience and not giving up.
``What happened to me could have ended so differently. I shouldn't have survived.
``What it did instil in me was that I survived for a reason, so I need to get out there and live life to the full and show as much of that as I possibly can through some of the crazy things that I do, like skydiving and bungy jumping.''
Ms Barrett has a mechanical right hand, and detachable lower legs which fit on to titanium rods implanted into her remaining leg bones.
``That gives me independence because I can take them on and off by myself, whereas before I had to rely on [partner] Craig or a friend to do that for me.''
A former oil and gas sector worker, Ms Barrett has reinvented herself as a motivational speaker and mentor.
Rather than be defined by her amputations, Ms Barrett has defined them in her own terms.
``It's rewarding, it's impacting lives, and that's the big thing I get out of it,'' she said.
``If I get a message from a student saying you changed my life today, or I've been in a dark place and you helped me come out of it, you can't put a price on that ... it's so much more rewarding what I do now.''
