The tennis coach, whose oldest son Jamie is also a Wimbledon champion, said that if she had been the father instead of the mother of two prominent tennis players, her appearance at matches would not have engendered such a negative response.
Mrs Murray, 54, said that she had been deemed "the worst thing since sliced bread".
She said: "I think if I were the dad of sons, I wouldn't have been noticed. There's something about a competitive mum, especially when the children are male. Boris Becker had a go at me a couple of years ago, saying Andy wouldn't win a slam until he got rid of me. I thought: 'I've never met you. You don't know Andy. You don't know anything about us'.
"But because Boris was saying it, I thought people would think, 'She must be an absolute nightmare'."
In 2011, before Murray won the US Open and Wimbledon, Becker questioned whether the Scottish player should distance himself from his mother in order to win a grand slam.
But Mrs Murray said of her reputation: "I have my own life and I'm always busy. If I want to see my children, watching them play is often the easiest way.
"I don't smile when I watch Andy because I'm totally focused. If he looks up, he doesn't want to see me laughing. But if you ask anyone else I work with, I love having fun."
She praised her son's new coach, 2006 Wimbledon ladies' champion Amelie Mauresmo, and gushed about another woman in Murray's life - his girlfriend Kim Sears.
"She's fabulous," she said. "I tell Andy how lucky he is. She makes amazing red velvet cupcakes. I'm serious about cake. A Victoria sponge with jam in the middle and icing on top is heaven."
The Great Britain Federation Cup captain, who is launching a project to get young girls into tennis, said of her previous role as her son's coach: "In my case I always recognised my limitations and wanted to find the right person to work with Andy at the right time. That was what mattered. His new choice is great."
She told Radio Times magazine that she only gets emotional about her sons' wins when she is in her home town of Dunblane and she described the moment in 1996 when she heard about the shootings in the school, where her sons, then 10 and eight, were. Sixteen children and their teacher died.
"When you've gone through a really dark, tragic time, and then come to a real high, I hope it helps people to feel something really positive about the town," she said.
She recalled driving to the school after hearing about the shooting and then waiting for hours before finding out whether her children had been involved.
She said: "A policeman came in and said that the parents of children from Mrs Mayor's class were to leave with him. The girl sharing my chair said, 'That's my daughter's class'. I don't know if I have survivor's guilt, but I had an awful moment then when I was so relieved it wasn't my kids. And then feeling terrible. She lost her daughter.
"I can't really remember when I first saw Jamie and Andy again. All they had been told was that there was a man in the school with a gun."
She said: "Andy's class had been on their way to the gym. That's how close he was to what happened. They heard the noise and someone went ahead to investigate. They came back and told all the kids to go to the headmaster's study."
She said of the massacre: "For days afterwards Dunblane was a ghost town. No-one went out. I had friends who had lost children, so I went to the funerals. It was impossible to believe something like that could happen in your little town. Sometimes it still is."