1212 GMT June 15, 2021
Margaret's woollen masterpiece is on display at Norfolk Makers' Festival in Norwich until 11 June, and is raising money for three hospitals in the county.
She started working on the knitted estate in 2019 and it became a lockdown project. She said she lost count of how much wool she used for the project, but said she worked on it for around "10 to 12 hours a day".
"It's always rewarding to see the people enjoying themselves looking at it and saying it's amazing," she said.
Margaret has also knitted the "NHS Knittingale" a woollen version of the COVID-19 Nightingale hospitals.
"I just thought, if I can think of something to do that we can show to people, and raise money for a charity, it would be something worthwhile doing," said Margaret.
Sandringham House was built in 1870 and has been the private home for four generations of British kings and queens.