But what transpired on the show was nothing short of breathtaking.
The 38-year-old mum of two, married to British musician Example, came onto the show with all guns blazing - and that's no understatement.
Over the two week course, she persevered, prevailed and put in every smidgen of energy she had to complete the harrowing challenges.
She made it right up to the penultimate episode, pipped at the post with just five remaining celebs outstripping her.
But while she didn't technically complete the course, Erin won something else from that experience - the attention of Aussies the country over who were not only impressed with how well she'd done, but were also jumping at the bit to work out how she managed to do it.
Being a busy mum, you'd think Erin would have a million other things to get through before even thinking about a workout.
But as she tells Now To Love, it's all about balancing things the right way.
"I feel like I kind of have it figured out now," she tells us of her sons Evander and Ennio.
"My youngest is now three and he's starting to become a lot more independent, he's in daycare, so just two days a week I have my little one at home and my other one is in school."
"That means I get three days to balance training with work commitments and personal commitments."
"It's important to make sure you actually allow time for yourself," Erin adds, before explaining that she also cherishes quality time with her sons.
"With COVID, my husband is also around all the time - he used to travel five months of the year. It's been great because he loves doing everything together, so we often train together too."
As for her diet, Erin admits that's taken a little longer to nail.
"We struggle a lot with figuring out meal options that suit both myself, my husband and also the kids. Our five-year-old eats pretty much anything, but our three-year-old is so fussy."
"So we eat quite simply," she continues. "My husband loves cooking, so I tell him to simplify everything. And when he's not home I live on green veggies, salad, and protein. Whether that's a steak or pesto chicken on the barbecue."
"You just need to stick to simple, easy meals that are quick so you can get back to being a mum," she continues.
While Erin's been put through a literal wringer after her stint on SAS Australia, she's showing no signs of slowing down.
And she's as keen as ever to continue challenging herself.
"When I got back from SAS it left a bit of a hole - but Pepsi Max approached me about doing the Taste Challenge and I was like 'Awesome! Another challenge for me'".
The brand are inviting people from all over Australia to also take part in the classic Cola vs. Pepsi debate, and they've illustrated it by getting Erin on board to taste both drinks while doing something a little tricky.
Participants are encouraged to share their own challenge with the Instagram and TikTok hashtag #FlavourFavourstheBold.
Hoping to challenge herself, Erin tried the taste test by doing it while hanging off monkey bars blindfolded after doing several sit-ups.
"It was still quite challenging actually, not the actual taste test itself, but doing the monkey bars blindfolded was," she explains.
But in comparison to SAS? "Not particularly," Erin laughs.
And as for whether she'd do something as tough as the show again?
"My ego says that I would do it again, but I'm not sure I could handle it. Knowing what was to come would be worse than not knowing I think!"
This article originally appeared on Now To Love.