But Rachel, from Glasgow, has beaten her stammer thanks to a speech programme and is delighted the star has spoken out to encourage other sufferers.
“Being asked by teachers to speak in class was a big worry because I was so ashamed of my stutter,” said Rachel, 32. “If I was having a bad speech day then I literally couldn’t talk.
“Some teachers could definitely have been more supportive. In one class we were going round the room saying the numbers and I just couldn’t do it.
“I was mispronouncing mine on purpose as I struggled to say ‘S’ and he kept going, mocking me and almost laughing with the class. That was definitely the worst teaching experience but other pupils would mimic me.”
Rachel says she couldn’t even consider university. Meeting strange people would have been a nightmare as she couldn’t answer the simplest questions about herself.
“It was absolutely horrendous,” said Rachel, who works for Barclays Bank.
“Life was very difficult. I would try and avoid speaking unless I had to. At work I would put my phone on silent to avoid calls.
“I would come in physically exhausted at night. My tongue would be sore from trying to get words out and my chest would hurt from trying to get proper air in my lungs.
“Friends and work colleagues were great but I felt I couldn’t be the person I wanted. It was impacting every part of my life.” If she missed the last train home Rachel would walk miles to avoid having to ask for a fare on a bus or to call a taxi.
Even the most basic of things became an agony of avoidance.
“All I wanted to do was go into Starbucks, order a coffee and be able to tell them my name to write on the cup.”
But there were also much bigger issues to be faced.
“I always wanted to get married and become a mum and I couldn’t see how I was ever going to be able to meet somebody and do that,” she said.
“And if I had children I wanted to be able to say their names without stuttering.”
Rachel heard about the McGuire Programme and when she signed up for a five-day course it had a transformative effect on her life – not only did it cure her stutter it was also where she met her future husband.
“It totally changed my life,” said Rachel, who has two sons – Samuel, two, and Toby, one – with teacher Adam, a fellow stutterer she met on the course.
“There were the physical things I learned about breathing and attacking words but the psychological side resonated most.”
Having a movie star like Blunt speak out on the issue can only be a good thing, according to Rachel.
“What she’s doing is really important,” said Rachel. “Someone who is struggling with their speech and trying to hide it can see Emily’s success and how she has been able to overcome it.”
Blunt may have a flawless accent as Mary Poppins but the mum-of-two said her speech impediment was still a concern.
“I will always be a stutterer,” she revealed. “I still stutter if I’m tired… I’m really bad on the phone.”
Rachel added: “It’s nice to see everyone is human.”