But as she donned a wig and women’s clothing and steeled herself for the public reaction, she had a very pleasant surprise.
Because far from being abusive, people were actually very accepting.
Rachel recalls: ‘When the time came to go out there in public, I was of course very scared about how it would go.
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‘However, it really could not have been any more different than I expected.’
Rachel says the community of Portsmouth ‘embraced her’ and have since allowed her to feel at home in her skin.
She says: ‘I really didn’t think people would accept me. It really shocked me.
‘The city has been surprisingly supportive and has truly backed me.
‘I thought people would turn their heads and shout abuse, but the reality has actually been much more welcoming.
‘It was genuinely such a surprise.’
Rachel, who lives in Southsea, adds: ‘I had dreaded walking down Commercial Road and parts of Buckland and Somers Town.
‘It was so emotional to know that all the abuse I had been expecting was just in my head.
‘I think for years I had truly worried about how people would take me if I decided to do it and I guess that really played on my mind a lot.
‘It’s taught me that I’ve got to learn to trust in people a bit more and to have faith in the city that I live in.’
Rachel had been Mike Duncan for the past 49 years.
But last summer, she made the decision that she didn’t want to live as Mike any more.
It was a big decision for Rachel, who was married at the time with a nine-year-old son.
But it was one she had been thinking about ever since she was a child.
Rachel says: ‘When I was growing up I identified myself as a female and it felt almost like I had been born in the wrong body.
‘My family gave me so much support back then.
‘When I moved into the adult world I made the decision to join very masculine professions, which I guess was something you wouldn’t really expect.’
For 10 years, Rachel was in the armed forces.
She served in both the army and the navy.
She says: ‘I think, looking back, I would never have had the courage to have come out back then.’
‘It would have probably left me more open to abuse as the attitude back then was not very accepting at all.’
Rachel’s marriage of 18 years fell apart last September, a few weeks after she came out.
She explains: ‘It was just the right moment for me.
‘It gave me the time to really gather my thoughts and work out who I really was.
‘Everything is still amicable between us but we don’t live together.’
Rachel says she had been cross-dressing for years, but stopped when her son was born.
When it came to explaining the decision to become Rachel to her son, she praised the way schools are teaching children about transgender issues.
She says: ‘I decided to sit him down and explain the whole thing to him.
‘We have raised him to very much be an open-minded child and he really showed that to me when I was talking to him.
‘He took it so well, making it seem as if it was almost not a big deal at all.
‘To him, the world just kept going as it had before. There was no massive change in the way his life was.
‘Of course, the breakdown of the marriage was never going to be easy for him.
‘But he showed me that there was never really any reason to be concerned about talking to him about it.
‘I think the way schools are teaching kids these days is something we should be proud of and it will make decisions like the ones I made so much easier for transgender people in the future.
‘They are the future generation and if they are on board with it then any kind of stigma that was once there will be long gone.’
Rachel is planning to undergo surgery to give herself female features and remains very positive about her future.
She says: ‘I’ve decided to do it as for me it will give me the chance to have the body that I always felt that I should have had.
‘I took a while to really think about it, but it’s absolutely something that I want to do.’
Rachel says she want to thank the city of Portsmouth and its people for accepting her.
‘Not in a million years did I think people would accept me, so I just have to say, through The News, thank you to all.
‘Sometimes this city gets a poor reputation, but in the end there really was nothing for me to worry about.’