She told BBC Radio Scotland’s Good Morning Scotland programme: “It was a young woman who was digging her car out that had been stuck there and she found it, took it to her mum who thought it might have been one of the school kids’ laptops, so contacted the school WhatsApp group.
“The bus driver said ‘I think I know whose that is’, and got in touch with my friend Ingrid with whom I’m staying – because Shetland is that sort of place, people knew that I was friendly with her – and she went and picked it up from Rachel’s mum.
“What is amazing is the support I’ve had from Shetlanders and I’d like to say a huge thank-you to Shetland, they’re there struggling with no power, with trying to keep warm, to get people fed and there they were keeping an eye out for my laptop, it’s classic Shetland and I hope that they all get reconnected and warm soon.”
Fans have now called for her to dedicate a character in the unfinished novel to Ms Wiseman.
The author, whose books have been adapted into the television series Shetland, said the data on the device may be retrievable.
Responding to one person who asked whether the data on the device is retrievable, she wrote: “Don’t know. Will have to consult an expert.
“But I had email attached my novel to myself a couple of weeks ago so not too much will be lost.”
The Scottish Government declared a major incident for Shetland on Tuesday after thousands of homes were left without power on Monday evening following significant snowfall.
Engineers from Scottish and Southern Electricity Networks (SSEN) Distribution are working to reconnect around 1,700 properties in the area that remain without power.