With a world record to secure her Commonwealth Games golden glory, Wollongong's Emma McKeon has become Australian swimming's reluctant superstar.

At some point after watching her brother swim at the London Olympics two years ago, Emma realised she also has what it takes.

It wasn't jealousy, or sibling rivalry, but rather a switch was flicked inside.

Up until 2012, Emma had been unsure of her future in the Australian swimming landscape.

Since then, she has emerged from ultra-shy teenager to the next queen of the pool.

It's hard to say she developed a killer instinct, because anyone who knows Emma will tell you she's too nice for such a cut-throat attitude.

But along the road of personal discovery, Emma is starting to understand what she is capable of.

"I wasn't expecting any of this," Emma said after winning the 200m freestyle gold in a Games record time of one minute 55.57 seconds.

"I'm speechless.

"My family is just very proud of both me and my brother and they are just excited to see it."

Not content with individual success, Emma also played a key role in the Australia relay team smashing the 4x100m relay world record, setting a mark of 3:30.98 with Bronte Campbell, Melanie Schlanger and Cate Campbell.

This columnist first interviewed the McKeons in about 2010, as they were first feeling their way on the Australian and world swimming stage.

While David had a confidence and quiet intensity about him, Emma was so reserved her father Ron directed me in her brother's direction for an interview.

But knowing her as well as anyone, David was hardly shocked by Emma's smash hit success in Glasgow.

"I knew she could do that," David McKeon said. "She's pretty amazing my sister, what she does in training."

David finished with silver in the 400m freestyle final on Friday morning (AEST), but was impressive in turning faster than Paul Biedermann's supersuit world record pace with 100m remaining. Before the final, but after McKeon had set the fastest pace in the heats, the greatest of all time, Ian Thorpe, labelled David the "best swimmer we've seen in 10 years".

Yet, it was Emma who stole the limelight on day one with two gold medals, to put Wollongong on top of the Commonwealth Games swimming medals table.

It continues a fine family tradition after Ron competed at two Olympic Games and mother Susie (formerly Woodhouse) was at the 1982 Commonwealth Games, while uncle Rob Woodhouse was also an Olympic swimmer.

Speaking to the Mercury as far back as May, 2013, after Emma had impressed in qualifying for last year's world championships in Barcelona, her father Ron knew she was on the path to glory.

"No doubt she is a different girl to how she was 12 months ago," Ron said.

"There's a real purpose about her and she's believing the Australian team is where she belongs.

"It's not about missing out on London - that's an extrinsic thing that only lasts for a short period of time - it's a maturity within herself which is intrinsic."