Yes, I think you need to hire a lawyer to help you with the application.the only concern for me is should I include my common-law partner into my application showing he's accompanying/ not accompanying... to be frankly we'd like to manage it as "not accompanying" , but on the other hand, I don't want to take the risk for my application (if the officer's doubt for the non-accompanying reason and not persuadable) ,if so, what reason should I use for "not accompanying" but we have a Canada borned baby? or should I hire a professional for this application?
Or, I knew you are from Hongkong, Could you speak mandarin? if you can, you also can go to York forum to ask professional's idea for free.