However, she will still keep her outfits as a keepsake and in memory of a woman who she claimed 'felt part of the family'.
Mary, aged 89 from Epping, Essex, first started her career as a lookalike of the Queen back in 1988, but she had received comments saying how she looked like the late monarch since the age of 17.
During her 34 year-long impressionist career, she's appeared in various films and television shows including Doctor Who in 1988 and the comedy film Bullseye in 1990 alongside the late Sir Roger Moore.
When asked about her decision to retire, Mary said: “I mean, it’s a change of an era now, it’s all going to be very weird.
“I was watching the television the day before and felt that there was going to be some bad news, which of course eventually came and it makes you feel very, very, very sad.
“And then you do sort of realise that will be the end as far as I’m concerned… out of respect, I don’t think one should do anything.”
Although Mary believes her decision to cease her impersonation career is the right one, it doesn't come without a great sadness.
“I’ve just moved home… and I’ve got two boxes full of hats and I’ve just found somewhere to put them and I thought: I’m not really going to need them any more,” she said.
“It makes you feel very sad.”
Mary said she will most likely keep the outfits as 'they’ve been part of [her] life for so long'.
Despite never actually meeting the Queen, Mary claimed to have been part of the crowds on the Mall for her wedding and coronation.
She said: “I slept overnight in the road with my boyfriend, in tents. We got very wet and we got very lucky because one of the buildings there had a radio so we actually heard the whole of the service.
“And as they put the crown on her head, the heavens opened.”
When asked what she had learned from the late monarch, Mary explained that she has always tried to 'act like the Queen and to be nice to and respect people' and that there will never be anyone like Queen Elizabeth II again.
Mary said the late monarch was 'the Queen - not Queen Elizabeth, not the Queen of England, it was the Queen'.
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