Do they offer the ear checks for fluid in NSW?
Its worth getting this checked anyway, even though its not the most liekly explanation
My cousins daughter had delayed speech wich they eventualy figured out was caused by fuild in her ear (not sure if this is glue ear or not) and she had grommets put in. she's been like a different child ever since. She could hear well, but it was muffled IYKWIM.