It is most important that your son is treated with all haste as soon as the blood tests are done - he can't afford for his bone age to advance anymore. IMHO I would be asking that he starts corticosteroid treatment even before the results come back. After the results are back and he has been stabilised on corticosteroids then they need to consider other treatment to prevent puberty onset. Of course your daughter needs treatment too but could possibly wait 'til results of the tests come back.
DON'T let anyone tell you that you have to wait x number of weeks for a follow-up appointment to get the results. You need to have an appointment/consultation the minute the results come in. This has already gone on too long.
I hope you have been referred to an endocrinologist.
I believe that your children will have Classical SVCAH judging by your description and the severity of their bone age advancement.
