What Clipper said, in that organisers are aware of it, and amend the SI's to allow kids under a certain age for the cruising div.
There are two handed races / series that are less serious than the SSANZ stuff. The Barfoot and Thompson series jointly run by Gulf Harbour and Weiti is an example (I might get flamed for saying that isn't too serious, I mean its serious, just not as serious as the Tripple series, B&T is run in summer, while the Tripple is in winter, for a starter),
And Weiti run a short handed series with two mini series, his n hers and solo, which is a bit more relaxed than the B&T.
Anyway, the less serious races are more accommodating around carrying extra crew. A Mum and Dad crew did carry the kids in one of those series, although they started doing too well I think and another competitor started grumbling. Their's was a trailer boat so it could be argued that the extra weight of the kids on the rail added to righting moment and an unfair advantage.
Alternatively there are crewed races that do the same courses as the B&T series races (out of Gulf Harbour), so you can race with the kids and comply with the SI's. I'm not sure about the legality of using autopilots in a fully crewed race, it may fall under stored energy. Depends if you need an AP two up. We generally don't (we have a tiller that reaches the front of the cockpit, so knee steering while sail handling is straight forward).
I would say it depends how seriously you take it, if you are going out for a family sail and get mid fleet or worse, I can't imagine it being a problem. If you want to take podiums and win the series, then questions may be asked. (For the less serious club racing, B&T, def not. Would you race a 100 nm with 2 under 4?)