Police have done extensive searching of the Riccarton area, but have not yet located any items that would lead closer to her.
With the cold temperatures and forecasts of -1 in the week ahead, there are concerns for her health.
"For anyone with CCTV, Police would like you to review any footage you have from 6.40pm on Wednesday 4 June to 8am on Thursday 5 June.
While Lis went missing in the Riccarton area, she is physically strong, and may have walked some distance."
Her husband of nearly 60 years, Gary Nicholls, has requested privacy, but said she is someone who always put others first.
"Her life has been about helping people, through nursing, Plunket and social work. She has been there for people when they needed help, and her influence has touched all our lives for the better," he said.
“We are also grateful to Police, the Search and Rescue teams, Canterbury University students and the Victoria Neighbourhood Association, who have been dedicating so much time and resource to help us find Lis.
“You have been working in the cold, the rain, and the darkness to bring Lis home to us, and we are incredibly grateful.”
"At this stage, we don't suspect any foul play, but of course we've got to keep our minds open." Aldridge said.
Aldrige says while Nicholls frequently went walking with her husband, but never by herself.
"This behaviour is uncommon now," she said.
Anyone who sees Nicholls should ring 111 immediately and use the reference number 250604/5465. Non-urgent information can be provided online at 105.police.govt.nz, using “Update Report”, quoting the same reference number.