Parliament had made improvements and adjustments to help her, including fully funding note-takers in the House and select committees.
But she still faced challenges in her first term, and glimpses of discrimination.
Last week, she was attacked for making an 800km trip at an estimated cost of about $550 from Christchurch to Masterton to be interviewed on a community radio show which focused on people with disabilities.
The Taxpayers' Union, a right-leaning lobby group, questioned whether the trip was fiscally and environmentally responsible.
Ms Mathers says the attack was "nitpicky" and failed to understand MPs' roles and responsibilities.
"All of us have to work with the communities that we represent, and that does involve travel. I thought it was bizarre, to be honest.
"I work hard to reach out to a community which is desperate to have its voice heard."
Parliamentary Service records show her expenses for the last quarter were $18,865 - about average for an Opposition MP. All Green MPs offset their travel by buying carbon credits.
But most of all, she says, the lobby group's attack failed to grasp what a hearing-impaired person could and could not do.
The Green MP did not want pity. But she did expect some understanding of her disability.
"There's no real substitute for face-to-face contact," she says.
She could not lip-read on Skype and needed to be in the same room for important meetings or discussions, such as an hour-long radio interview.
"Communication for me is like a jigsaw puzzle," she says. "I get a little bit of this and a little bit of that. And then I think that someone must have said this, because that's the only thing that makes sense."
The National-led Government had been "incredibly co-operative" in making changes in the House, she said. Ministers had begun sitting as close as possible to her seat when she was scheduled to ask a question at Question Time, to make lip-reading easier.
She could not speak on all the bills she wanted to because note-takers were not always available, so instead she picked a handful which she felt most strongly about.
Ms Mathers says the most frustrating aspect of her disability is not being able to do spontaneous interviews for radio.
"The only way I can provide a soundbite is either face-to-face or if I'm on my [captioned] telephone, which is only good for pre-record, not live. That's where I miss out on being able to have an input."
The MP does not socialise much outside Parliament hours, partly because she prefers the quiet life but also because she is exhausted at the end of most days.
"It definitely uses more energy to keep focused, to keep up with conversation, doing that all day is like being on high alert all the time, to make sure I'm getting all the clues I can to make sense of what's happening.
"Its just something I've had to learn to manage."
Ms Mathers has always been deaf. Her birth at St Pancras Hospital in London "took too long", starving her of oxygen, and the damage was discovered when she was 2.
"My local kindergarten teacher said to my mother, 'Do you realise your daughter can't hear, and that's why she's not speaking'."
Ms Mathers was given cumbersome hearing aids which hung off her body on a harness. Her mother, who named her after a Muddy Waters song, taught her the words for objects by using a doll's house and its furniture for props, and then used children's books to teach sentence structure.
"When you're deaf, you can miss out the small words like 'and', 'is' and 'at'. So that's where reading comes in," she says.
After relocating to New Zealand with her family in 1981, aged 14, she was dux at Karamu High School in Hastings and studied mathematics and forestry at the University of Canterbury.
A mother of three, she came from a Labour family but when an extensive irrigation scheme was proposed on the Waimakariri River near her home, she felt that neither Labour nor National was taking water protection seriously enough.
On entering Parliament on the list in 2011, she opened her maiden speech with a Maori greeting called "My river is my life".
Her first headlines were about who would pay the bill for her note-takers, but she has since had some victories on policy.
Her high point was forcing the Government to block legal high manufacturers from using animal testing if there were alternatives available.
Disability advocates who have been desperate for direct representation say her most important achievement was simply becoming an MP.
There is a letter from a fan on her office wall that says: "You are the expert on the needs of the community - not the Taxpayers' Union or anyone else."
Lobby group rejects claims it has right-wing bias
The Taxpayers' Union says it will fight wasteful spending of public money wherever it sees it.
But since emerging last year it has been accused of being a soapbox for right-wing interests.
This was accentuated when it criticised Green MP Mojo Mathers for spending an estimated $550 on plane and train tickets to speak on a rural radio station about disability issues.
The lobby group was formed in October by John Bishop, a journalist and media trainer, and Jordan Williams, a commercial lawyer. Its other two directors were National Party pollster and blogger David Farrar and Gabrielle O'Brien, a sales executive at a software company and former Young National regional chair.
The union described itself as a non-partisan activist group "dedicated to being the voice for Kiwi taxpayers in the corridors of power".
Some questioned why its targets appeared to be mostly spending by left-wing councils or parties, and not Government splurges such as the $209,000 spent on finding a leak at the Ministry of Foreign Affairs and Trade.
Mr Farrar said the Taxpayers' Union had attacked the National-led Government far more than anyone else. Its archive of press releases showed that its targets were varied.
The group had publicly criticised ministers for claiming subsidies on their investment properties and Prime Minister John Key for approving higher wages for MPs.
It had been particularly critical of Economic Development Minister Steven Joyce for subsidising the sheep and beef sector and for "picking winners" by giving out research and development grants.
Its main targets have been the Auckland Council and Mayor Len Brown, high passport fees, and the living wage campaign.
