But, from Thursday, Mrs Callander will officially be retired.

"My heart's not ready to give up, but the body is. I've loved every minute of it," she said.

"Some of it's been rather challenging, but the rewards ...there's just so many.

"You go home and just thank your lucky stars you've got such a great job. I still plan on coming back and visiting.

"It's the little things that count. Someone who can't recognise a word one day and does the next, or may come up with a great story that you've helped them write.

"Just this year, one of our students got his licence while he was still at school and that's the first one in 20 years. That was very exciting. He still comes in to visit."

Kooringal High staff organised a range of special celebrations to mark Mrs Callander's last day.

Former teacher Danielle Rheinberger travelled from Alstonville to be there to say goodbye to the woman who saved her life.

Mrs Rheinberger was just 36 - and had been working with Mrs Callander for only a matter of weeks - when she suffered a stroke at school.

Mrs Callander immediately recognised the symptoms of a likely stroke and organised emergency care for her colleague.

Reflecting on her final day, Mrs Callander said she had not expected to remain for so long in the job she initially took on a temporary basis.

"When the unit started in 1999, they didn't have anyone for the position and I was looking for work," she said.

"I still had a daughter here and they thought I might like to fill in. So I did that for six months and then applied for the job and got it and I'm still here 20 years later."

Mrs Callander and her husband Graeme are planning to take a cruise and then there's the opportunity for more time with the children and grandchildren.

"The staff here have been fantastic. It's been a pleasure coming to work every day. I'm going to miss them all," she said.