JA Girl
Very unlikely at this point as admissions and such have already been handled at the better schools. Still worth making a morning of phone calls and getting them on the lists. Most school preference siblings, so once one has a place at the school you want, the other will soon follow. Most people I know usually have to wait about a year unless they are with one of the school's sponsors, which means a reserved/preferential place.

As for the earlier comment about about all the schools being run like businesses that is entirely untrue. Some are profit-making, including some of the decent ones like Sherborne and Compass, but DESS is definitely not-for-profit and neither is Doha College (I think), which in my view are the best primary schools in Doha.