It's a good idea, but the schooling thing is not gonna happen.
For what reasons?....waiting lists, paperwork, medical checks, uniforms ...you would need an international school/kindergarten otherwise there would be no hope of anyone understanding your child's blubbering if they got upset (new country, new language) and you were in Discovery Bay.
There's not much choice in QB either. There is the QB ESF school which takes kids from 5 and is also full. There are heaps of little local Kindergartens which are unlikely to take short-term. If you want to try I will get some phone numbers for you.
I think your best bet is to get a native English speaker from one of the agencies and lots of DVDs. There is also a fantastic playground for that age group close by in Taikoo which she could take them to. Also a big Toys R Us Lol.
Another thought, if your visit co-incides with school holidays you might try QQ Club in North Point. They have full-day activities in English. Very pricey and you also have to pay a joining fee of 1200 per child.