Hi Jane
Your eldest son will have to remain dependent on you even after the 457 visa is lodged as when you go to get
PR he will still have to qualify as a dependent to be on your
PR visa. This has happened to my 17 year old & at present he is working in a fast food place part time until we get
PR. Then he is going to college here but only when we get
PR. I feel really quilty about this as he passed all 8 highers with flying colours in the UK but his life is on hold for a year but mind you considering he didnt want to come or stay in Oz but has now settled its not that bad. Hope this helps.
Janette