The Mandurah woman is a criminal defence lawyer for Petherick Cottrel Lawyers.

"I've always known I wanted to go into law - it's all I ever wanted to do or talk about to my parents," Deearnah said.

"When I finished high school I went straight into law at university and got a double degree in law and criminology, which took about six and a bit years to finish."

While Deearnah was at university she discovered her passion for criminal law through work experience with some of the leading criminal law barristers in Perth.

"It really clicked for me when I started doing work experience.

"I started looking for criminal law barristers and I followed them around carrying their suitcases and sitting in the courts watching them in action.

"This gave me a real interest in criminal law - especially the idea of helping people to access justice."

When Deearnah began shadowing a barrister who worked on a number of wrongful conviction cases, a spark was ignited in her, and she said she immediately knew what she wanted to do.

"The barrister I worked with did it all as pro-bono work - for free - and he had a real passion.

"I didn't even really know wrongful convictions were a thing - I was gobsmacked that there were people out there who were imprisoned for things they didn't do.

"Working on those and being able to help someone who has spent the last 10 years in jail for something they didn't do ... it's incredible to be a part of that.

"When you think about it - who else have they got to help them except for criminal defence lawyers?"

Once her career as a criminal defence lawyer started, Deearnah began to notice people being surprised by her presence in court.

"I'm quite a petite person - I'm small, and a few times when I turned up to court I could sort of see the look on my clients' faces if I hadn't met them before - it was like 'is she a lawyer?', "is that MY lawyer?'" she laughed.

"I used to get really offended but I just laugh it off now and prove them wrong in the courtroom - I let them know not to let my size fool them."

Deearnah said criminal defence lawyers sometimes got a bad rap from the public, but the work was important in so many ways.

"When I say I'm a criminal lawyer people will say 'do you put bad people away?' - that's not exactly how it works, and people can get very one-minded when you say 'no, I'm a criminal defence lawyer' and they say 'what - you defend criminals?'

"I'm in this industry and it's not like that at all - these people are often ordinary people who find themselves before a court for things you wouldn't even think of.

"Sometimes we defend people who have had their dog escape and bite another dog - you wouldn't even think you'd appear in front of the court for something your dog has done.

"Then there are those who are innocent or who were defending themselves - where they've completed an action in self-defence but are being charged with assault or another serious charge.

"Our job is to say 'no - look at the facts, look what happened' and to prove they acted in self-defence."

Deearnah said she had some advice for anyone wanting to enter the legal profession.

"I know that through uni and applying for jobs it can be a massively pressured environment, and you can doubt yourself and think you're not good enough - but everyone has been in that same position.

"Everyone started at the bottom and worked their way up - be motivated and determined. When you face hurdles keep remembering that things will come to you eventually, it's a rewarding career and you will help a lot of people."

When Deearnah isn't in the courtroom, she is soaking up sun in the great outdoors.

"I'm a really outdoorsy person - my husband and I love the outdoors. We've got a boat and our Harley and we like to cruise down the river to the Ravo for a few drinks.

"Sometimes the job has long hours and you spend a lot of time either in an office or courtroom so getting outdoors is a really good way to get back that life balance."