Speaking to Ryan Tubridy on RTÉ Radio One, the Northern Irish singer said the last few weeks since Harding’s passing had been “awful”, and it has been a “really traumatic” year and a half since Harding first fell ill.
She said: “It’s a cruel, cruel disease and I know many people are suffering with it and I wish everybody all the best, but we definitely lost one of the great ones.”
She told Tubridy that Harding has “definitely made her presence known a few times” as she filmed for a new show, Last Singer Standing.
She said: “There was a couple of days when my headphones just flew across the table when I was sitting getting my make-up done. It happened three days in a row for no reason, just flew across.
“The girls in hair and make-up were saying, ‘it has to be Sarah, there’s no reason why they would fly so far.’
“I was talking about her one night in my house and something went flying off a shelf. I was like, ‘is this Sarah? Is she just like, throwing stuff?’
“I’m kind of in this thing that it’s so fresh I’m still thinking ‘she’s going to phone’, I’m still in that stage of it. And then stuff was flying around and I’m like ‘could that be?’”
Tubridy asked if she finds some comfort in these signs, and she said yes.
She added: “The hair and make-up girls were running screaming, they were like ‘not again! What’s happening?’ and I was just kind of looking like ‘maybe it could be, could it be?’. You know, you just want her to send you a text and be like ‘yeah it’s me, I’ve just thrown your headphones at you’ or whatever so yes, I’m still in the processing stage of it.”
A week after Harding’s death, Coyle uploaded a touching tribute to her friend on Instagram.
She wrote: “Thinking of you all day everyday and trying to imagine how your new journey is going.
“Please feel free to come visit me anytime. I know lots of people will want some Sarah spirit time so I can wait my turn.
“I hope you now know how much you are loved and how you impacted so many lives by being wholeheartedly yourself. Always an inspiration, always a shining light and always my friend!”
Coyle and Harding met on Popstars: The Rivals in 2002 where Girls Aloud was formed.
The group, made up of Coyle, Harding, Cheryl Cole, Nicola Roberts and Kimberley Walsh, performed together for 11 years, releasing chart-toppers such as Sound of the Underground and The Promise.
As a group, they released 20 consecutive top 10 singles, with four of them claiming the top spot on the charts.
The pair remained close friends during and after their days in Girls Aloud.
Although Girls Aloud were due to have a reunion to mark their 20th anniversary next year, Walsh told The Sun: “It’s not really something we’re even thinking about obviously, with the situation as it is. No one is even in that headspace right now.”
On Tubridy’s show, Coyle also spoke about the pandemic, motherhood, and her upcoming stint as a judge on a new RTÉ TV show Last Singer Standing.
As the production company that ran Popstars: The Rivals is the same firm that is now running Last Singer Standing, she said she has met people she hasn’t encountered since she was 16.