Rugby league pin-up Craig Wing never considered his youngest sister Kirsty as anything out of the ordinary. Growing up in a working class area of Sydney, he was protective of all four of his sisters.

The fact Kirsty, 18, has Down syndrome had no impact on Craig's unconditional love and support. But as she looks forward to life after high school, his brotherly instinct is kicking in even more.

'I've looked at Kirsty as another one of my sisters - she's one of the girls,' he says. 'She's held her own, I don't look at her differently.'

Craig is proud of Kirsty, how she lights up a room and takes the spotlight from him.

'It astounds me when people meet her, and within about 30 seconds, she has them wrapped around her little finger,' Craig says. 'She plays on it too. She's quite a smart girl.'

But Craig also wonders if Kirsty will be able to hold her own in the real world.

'I'm a bit scared for her,' he says. 'It's a significant point in time. She's growing up. I suppose we'll always see her as the baby - she's the youngest, so it's inevitable. Now we have to think about whether she'll get a job and how she'll get around.'

Craig's looks make him every woman's dream, and as a professional footballer who returns to South Sydney Rabbitohs next season, he knows a part of him is public property.

'That's the way it is these days,' he says.

When it comes to his family and those around him, though, he's more guarded.

But as Kirsty contemplates the biggest milestone in her life so far, Craig is sharing his concerns in the hope that families of people with disabilities, in particular Down syndrome, realise they're not alone.

'I know she'll be fine, but it's something families of anyone with a disability face - what happens when they leave school?

'We've got a big family, but Mum works full-time and I'm pretty busy so it's hard to have someone around the whole time.'

Craig was so intent on Kirsty's transition to adulthood going smoothly that he went as her date to an end-of-year school celebration.

'I just wanted to make sure it was a special night for her,' he says.

Star designer Charlie Brown ensured Kirsty was pretty in pink in a stunning Lili dress. It was Charlie who convinced Craig to wear all pink on an Australian Fashion Week catwalk in 2003, which he jokes is still a cause for embarrassment.

Now Craig has ramped up his support of Down Syndrome NSW, a charity of which he's patron. He's planning a dinner in April called On A Wing and A Prayer.

Strangely, it wasn't Kirsty who inspired his increased interest the charity, it was a chance encounter while dining with friends.

'When I walked into the restaurant I saw this girl with Down syndrome. She was about 20 and having dinner with her parents,' he recalls. 'She'd eat, look over, and look down then hide behind her parents.'

When Craig had finished eating, the girl, Shannon, came over with her mother.

'Her mum said she was a fan and as soon as she smiled it made me feel good. I wanted to talk to her. I realised then this is the effect my own sister has on people,' he says.