Mrs Hooper works two full days a week at the store on Port Rd, but does plenty of extra time at home.
She was shocked when she heard she had been chosen as a finalist.
"You don't go into this sort of thing for any sort of recognition."
After the shock subsided, she felt privileged.
"I look at it as, I'm part of a team. I'm not that sort of a person, I just put my head down and go."
And go she does. Senior co-ordinator Janice Webb describes Margaret as "the mainstay of the clothing department of our store".
Margaret takes the donated socks, underwear, bras, school uniforms and swimwear home and washes them in her own washing machine.
She sorts, repairs, irons, packs, prices and hangs the clothing.
The clothing is popular with customers, Mrs Hooper uses bras - they are selling an average of 100 bras a week - as an example.
She also tackles the shoes, sorting and cleaning them ready for sale.
As well, she takes home all the clothing items unsuitable for sale and her husband Brian cuts the buttons and zips off and the material goes to the SPCA kennels to be used as pet bedding.
If sorting out the donated goods wasn't enough - she knits slippers - about four pairs a week - and makes marmalade - 12 jars at a time, which are sold in the shop.
"I started off because they advertised they were short of helpers in their new shop, I thought I could do that, I'm retired.''
She is a firm believer in the need to keep busy in retirement.
"It's just snowballed."
Mrs Webb said nothing is ever too much trouble for the "just unbelievable" Mrs Hooper.
"She is an example for anybody, young or old, that you can keep going."
She said they don't know what they would do without her.
The winner will be announced at the end of the month. They will win a year's supply of cat or dog food and a $1000 Prezzy Card.
Mrs Hooper said she would donate the pet food straight to Whangarei SPCA's kennels and would consider upgrading her laundry system with the Prezzy Card.
