The mother-of-two was last seen at 11:30 am on January 13 after telling family she was going for a run at Mount Nameless, 10kms from the Tom Price town centre.
A Tom Price resident said Shadbolt regularly walked the area and was carrying a hydration pack and mobile phone.
News.com.au reported her last known contact was at 12.50 pm on Sunday when she sent a text message saying she would be home in about 20 minutes.
Police have not determined if the death is suspicious, and have not ruled out foul play.
Shadbolt’s family have been assisting police with the search, with her mother and older sister flying to the mining town on Tuesday.
“Thank you to those who have helped looked and are still looking for her,” her sister Jennifer Dick wrote on a WA Police Force Facebook post.
Friends turned to social media to express their heartbreak at the sad end to the search.
Shae McHarry wrote: “RIP Flik, such sad news to wake up to this morning. Thinking of Drew and the girls and all the family at this sad time.”
Rachelle McLean said she would be “missed terribly”.
Jodie Webster said her thoughts were with Mrs Shadbolt’s husband Drew, their twin daughters and their families.
“RIP Flik Shadbolt, fly high gorgeous lady,” she wrote.