(For starters tell me not to take my MA and take a PGCE to become one of you. I was a nurse for years and sick of being in a government policy led career).
At GCSE and A level do children use single or double quotation marks around character speech? Obviously the publishing conventions are single, I've been teaching my children single, the books they read have single, but I think primary school might be teaching double marks around speech ( how quaint & old fashioned or American ). They've been encouraged to write fiction from when they could first make coherent letter shapes so single marks are fairly ingrained by 10 years old.
If they will need to do double I'll bite my tongue ( possibly literally ) and encourage that (and rant in a quiet dark room by myself)). If they use single I'll ask her class teacher to bear with her use of them.