Like Lindsay, Thomas has spent a large portion of her life working on and off both full- and part-time in football after leaving the tax office for a role with the VFL in 1980.
She started her career in football operations, finance and membership, which was rolled into one department 30 years ago.
After most recently working as the finals ticketing manager in the commercial operations department and with AFL integrity officer Brett Clothier, she temporarily took on Lindsay's role following her passing from cancer in February.
Thomas said she was excited about the challenges of this season, with her role to be more critical with the introduction of Gold Coast and the opening of Metricon Stadium in May.
"I am thrilled to be able to do this after working in footy ops before throughout the past 30 years I've spent at the AFL," she told afl.com.au on Wednesday.
"I've certainly seen the AFL grow over that period of time. We had a much smaller staff and smaller departments when I first started here in 1980.
"It's like coming home to the department I first started with, so I'm very happy to be back here.
"It's nice to keep a woman in the role as well."
Thomas' first taste of the new role saw her oversee the recent NAB Cup and NAB Challenge series as Lindsay's stand-in.
She said she had learned plenty from Lindsay throughout their long time as colleagues and friends.
"We always worked well together from the very first day I started here," she said.
"Jill was unique and I'm a bit different to her, so we'll do things differently but I've always had a great admiration for her."
Thomas was recently captured in the moving video tribute to Lindsay's life and 40-years in football, with the pair filmed handballing to each other after hours at headquarters on an off-season Thursday night.
"She was terribly critical of me there, but my foot skills were much better," Thomas said.
Thomas will work four days a week in her new role with grounds operations and football logistics coordinator Tess McManus to provide assistance.
Football operations manager Adrian Anderson said Thomas' appointment - and McManus' promotion - were the efforts of hard work.
"This year's NAB Cup and NAB Challenge was one of the most successful we have had, especially when considering such challenges as the new triangular format," he said.
"I wish to congratulate Sandra and Tess and all the football and umpire department staff for their professional preparation for an exciting season ahead."
