Judy Murray: 'Anybody who knows me knows I am not a pushy mum'

If you thought you got nervous watching Andy Murray, spare a thought for his long-suffering mum. She experiences "a mixture of nausea and a heart attack" when he plays – and the feeling is getting worse.

"I think [I'm] more nervous nowadays as there's so much more expectation. I'm more nervous than I was the first few years when he played at Wimbledon and it was all new and a big adventure," reveals Judy Murray, who is due to see her son, the world number four, play the Russian Nikolay Davydenko at the All England Club on Tuesday. Maybe she should try a cup of tea and a lemon iced doughnut beforehand.

The 52-year-old does not have regular pre-match rituals, but last year inadvertently got into the routine of having this particular snack each time Andy played at Wimbledon. After having it before his first match, which he won, she decided it was her superstition. Andy made it to the semi-final. It seems like a good excuse to eat doughnuts. "I didn't say I ate all of it," she laughs. And her petite figure suggests she probably didn't.

Andy, 25, isn't the only Murray with a job to do at Wimbledon. His elder brother, Jamie, 26, will be contesting the mixed doubles, which he won with Jelena Jankovic in 2007, and the men's. And, for the first time, Judy will be there to watch the country's women players, as well as her sons. In December, she was named captain of the Great Britain Fed Cup team – the female equivalent of the Davis Cup – and she is also working to develop the number of female coaches. She is enjoying the challenge and responsibility, but admits there are a lot of people who just thought she was Andy and Jamie's mum. She has, in fact, been coaching for 20 years.

As a mum, she has attracted a reputation for being pushy and embarrassing – the latter particularly last year when she dubbed Andy's Wimbledon opponent Feliciano Lopez "Deliciano". When I ask her about the pushy parent tag, she avoids eye contact for the only time during the interview and seems embarrassed as she nervously laughs away the charge. "I think that anybody who knows me knows that I'm not a pushy mum," she insists, staring out of the window rather than looking at me. "And I think if you ask the boys – and they have been asked – they would say exactly the same, so I think a lot of the maybe criticisms that are levelled tend to be levelled from people who I've never met and just form an opinion from whatever they see, I guess."

What people often see are images of the Scot pumping a clenched fist as she cheers on Andy. In person, she is not remotely pushy; her demeanour is much softer than I expected. "I am competitive and I understand what are the big points ... and that's how I choose to show it, but it's not like I'm punching my fist in the air every single point. However, those tend to be the pictures that people pick up on," she explains. "I like to go and watch Jamie and Andy playing and I like to support them and I think it's very important over all the years that they've been competing ... that they get positive reassurance if they choose to look your way." It is a "normal parent reaction", she claims. She took a "step back" several years ago and does not travel to as many tournaments as she did but, with her sons out of the country for 30 weeks of the year or more, she would not have the chance to see so much of them if she did not watch them.

I suspect what might appear to some as aggression is motherly love combined with sheer passion for tennis. Judy shows her enthusiasm for sport when we discuss her Set4Sport programme. It is a collection of ideas for inexpensive activities, available through a website, free book or phone app, inspired by games she played with her boys when they were growing up. Community clubs and groups engaging parents and children can now apply for a free kit bag of equipment under the scheme supported by Royal Bank of Scotland.

Sport was part of Judy's upbringing in Dunblane, the Scottish town where tragedy struck in 1996 when the gunman Thomas Hamilton killed 16 children and an adult at the primary school, before committing suicide. Andy and Jamie were at the school that day. The town "has recovered amazingly well" since then, but she does not want to talk about it.

Her father, Roy Erskine, was a professional footballer for Hibernian, Stirling Albion and Cowdenbeath, and a keen tennis player. Judy played football and basketball with her dad and younger brothers, Keith, now a golf pro in the US, and Niall, an optician running what was their father's business. It was "second nature" for her to be active with her own children and she believes the games they played helped their overall co-ordination, balance and agility; Jamie also has a three handicap at golf and Andy once had a trial with Rangers.

Judy started playing tennis at 10 and got her first coaching qualifications when she was 17, helping out on Saturdays at the club where her mum, Shirley, coached. After studying French and business studies at Edinburgh University, she worked in retail management for Miss Selfridge before going into sales at a confectionery company. When the boys were little, she ran a toy shop with her mum, and became a full-time tennis coach from 1994. She was inspired to upgrade her qualifications by the progress of some other young players. "I think a lot of people who think that I was a tennis coach when Jamie and Andy were small and I brought them up to be tennis players. I didn't," she says. "I was just a mum who enjoyed playing sports with her kids."

When the boys were about 10 and 11, they played each other in a junior tournament final: it is an occasion that still makes the family laugh. "They videoed a little bit of it and it was quite funny because Jamie had a real cough ... and it [the footage] was Andy telling him to stop coughing as it was on purpose and it was putting him off."

That would be a novel tactic. Maybe Andy should try it on Tuesday? "Yeah," laughs his loyal mum. "Who knows?"

Curriculum Vitae

1959: Born in Bridge of Allan to Roy and Shirley Erskine.

1980: Plays tennis for Great Britain at the World Student Games. She had played professionally for six months after leaving school but "wasn't good enough".

1981: Graduates from Edinburgh University having studied French and business studies.

1986: Gives birth to her first son, Jamie, in Dunblane.

1987: Second son, Andy, is born.

1995: Becomes Scottish national coach, a post she holds until 2004.

1996: Gunman Thomas Hamilton enters Dunblane primary school, at which Andy and Jamie are pupils, on 13 March and kills 16 children and an adult before shooting himself. In Andy's autobiography, Hitting Back, Judy describes it as "the worst day of my life". She had given Hamilton lifts in her car in the past.

2007: Sees Jamie win the Wimbledon mixed doubles title with Jelena Jankovic.

2010: Becomes a mother-in-law when she attends the October wedding of Jamie to Colombian Alejandra Gutierrez.

2011: The Lawn Tennis Association appoints her Great Britain's Fed Cup team captain.

2012: The GB Fed Cup team loses the World Group II play-off against Sweden. KY