what I know is there are three IGCSE Chinese exam paper taken in IS generally.
a) Chinese as foreign language. ( looks like kinder level)
b) Mandarine as 2nd language. ( like primary p.4 level)
c) Chinese as 1st language. ( like secondary form 3/4)
If we are talking about staying in IS, what are good school options? ISF, SIS, CIS are all quite difficult to get in, especially since the child is already... 5, is it? Maybe CAIS since they start later, but are their Chinese good enough?