The pair will follow in the footsteps of older brothers Joe, Ollie and Fred, who have all worked as ballkids or in court services at one of the world’s most prestigious tennis events.

The Harrisons’ mother Buffy worked at the Australian Open as a statistician in 1993, a few weeks after arriving in Australia from the UK on a backpacking holiday.

‘‘My father had contact with the tennis back in England and thought it was a perfect way for me to make some money while I was over here,’’ she said.

‘‘It wasn’t until Ollie started having tennis lessons in Horsham that we thought about the kids becoming involved.

His coach suggested he try out as a ballkid and it went from there.’’

Ollie, 18, worked as a ballkid in 2010 and 2011 and in court services in 2012 and 2013.

Joe, 16, was a ballkid in 2011 and 2012, while Fred worked in court services in 2012 and 2013.

Mrs Harrison said the family was away during this year’s open, but Nia and Archie were keen to try out for the first grand slam of 2015.

She said the event provided children with a great life experience.

‘‘They live in Melbourne for three weeks.

"They need to be prepared for shifts, organise their uniforms, etc,’’ she said.

‘‘It’s a huge responsibility. You really notice as a parent how much they mature throughout the three weeks.

‘‘They get to enjoy city life. As soon as the open starts the city comes alive – it seems as if everyone is a tennis fan.’’

Nia and Archie said they were looking forward to the experience.

‘‘It’s so exciting,’’ Nia said.

‘‘We’ve watched the boys do it – we tend to watch the ballkids more than the tennis because we know some of them.’’

Nia said the field of hopefuls was cut three times before the final squad was determined.

‘‘Sometimes I thought I went well and other times I thought others did better, so it was hard to tell where we were at,’’ she said.

‘‘It was good having Joe and Ollie to practise with.’’

Both siblings are keen to see Roger Federer in action.

‘‘But just being there will be cool,’’ Nia said.

‘‘We can’t wait.’’

Nia and Archie are among 380 ballkids chosen from across Australia and the Asia-Pacific region.

Australian Open squad manager Tania Hall said 2500 applicants were selected in the first round in May following trials at tennis clubs across the country.

She said the top-performing ballkids from the Brisbane International, Hopman Cup, Apia International Sydney, Hobart International and World Tennis Challenge Adelaide were also invited to join the squad.

‘‘The kids become a part of a great little community and the tournament provides a really good environment for them to grow,’’ she said.

‘‘Their involvement in the program gives them the opportunity to be on court with some of the world’s best tennis players while developing their confidence and practical skills throughout the process.’’

Hall said ballkids played a vital role.

‘‘They provide quality service to international athletes and use their co-ordination, agility and balance to ensure the play runs effectively and smoothly,’’ she said.

● Nia will write a diary about her Australian Open experience for the Mail-Times.