The Invercargill-based entertainer attended a council meeting this week as a "concerned ratepayer", and watched Mr Shadbolt fail in his bid to oust long-serving deputy mayor Neil Boniface.
Asked how she felt after the meeting, Ms Prentice said she was still concerned and was seriously considering standing for the mayoralty.
"I am doing my homework."
She hoped to make a decision early next year.
The 51-year-old, who is in her second term on the Invercargill Licensing Trust board, said she planned to continue in that role.
Ms Prentice, who was born and bred in Invercargill, said she remained committed to the city "despite being told when I started my career 38 years ago: `You will never make it being based out of Invercargill'."
During her singing career, she has worked with country star performers Dolly Parton and Kenny Rogers, and was actively involved with the charity World Vision.
Mr Shadbolt could not be reached for comment last night.
