Emilia is described as 5ft 6ins tall, of heavy build, with grey hair, and is likely to be wearing purple glasses.
She may be wearing a blue T-shirt with small white flowers on, black trousers, and carrying a black backpack and an Asda shopping bag.
A police spokesman said: “Have you seen Emilia? The 53-year-old is missing from the Boston area and we are growing increasingly concerned.
“If you have seen her, or have any information that might help us in the search, then please contact us on 101, quoting Incident 252 of 13 November.”