MacKenzie's neighbors offered few details about her life. They said she mostly kept to herself, but they've seen her take short walks along the street and exchanged pleasantries with her.
Her house, situated among mostly mobile homes and pre-fabricated houses, has a chain-link fence with a sheet-metal roof and an old TV antenna.
MacKenzie retired to Zephyrhills more than a decade ago from rural Maine with her husband, Ralph, who died in 2005.
Back in her hometown of East Millinocket, Maine, relatives and friends were surprised to hear of her good fortune.
Robert MacKenzie, Ralph's brother, said the couple met just after World War II after Ralph got out of the Navy. He went to work in the town's paper mill, laboring as a technician for almost four decades.
He said the couple raised four children in East Millinocket, a town of less than 2,000 people in northern Maine. A daughter and son still live in East Millinocket, another son lives in Florida and another daughter lives out of state, possibly in Massachusetts, he said.
Robert MacKenzie said he didn't know his sister-in-law had won until a reporter called him.
"Holy mackerel," he said when told of her winnings. He added: "It hasn't soaked in, but I'm happy for her. That would be great because she's a widow and she can have a nice home now."
One of the MacKenzies' daughters, Melinda "Mindy" MacKenzie, a high school teacher, still lives in the family home in East Millinocket in a quiet middle-class neighborhood of white clapboard houses.
Ralph MacKenzie enjoyed snowmobiling, hunting and fishing, said Andrew Hopkins, a retired high school teacher and assistant principal who taught some of the MacKenzie children.
"They were good people. That's about all I can tell you," said Hopkins, who lives across the street.
Associated Press reporters David Sharp and Clarke Canfield in Maine contributed to this report.