Will my son get chickenpox?? please please comment..?

My son was exposed to a little girl who has had the chicken pox. We did not get a good look at her chicken pox but we spoke to the grandma on the phone and she says the girl had them two weeks before she flew out of england, then went to dubai for 4 days and then on her third day in australia we saw her.. i read its usually ok by 6 or so days after onset of blisters, what you think!!!???