My wife and I wrestled with that same question ourselves. At first I was set to put some info into our application that showed there was discussion around how we would/could face the challenge of getting married and going through the immigration process. We could of gone through inland or outland processes. Outland won out in the end.
But this is a subject that any forward thinking couple is going to have to look at if they feel the relationship is worth pursing to the "next" step.
At first I was all set (with reservations) to include a email conversation between myself and the marriage commissioner we used in Alberta. My reservation was based on my own usage of the words "make her legal" in my talks with the commissioner, in context of my state of mind at the time, and trying to get things buttoned up with my wife's work visa, her work situation, the challenges around trying to figure out what arrangements would be needed for her child back in the Philippines and other things, all coming together at one time.
There was nothing at meant in any un-toward way by the use of the words "make her legal", but on the face of it, someone maybe doing a quick scan over documents sitting at a desk in some office somewhere towards the end of a long day, it might of given them just enough reason to pause and take a second look at our paper work.
So after discussion with my wife, and her somber second thought, reiterating my initial concerns that one piece of the package was left out, if for some reason it is needed later no problem it can be produced and explained then.
Now just a little over a month into the process, I think we made the right choice to not include that bit, at least not now, as we have received our first stage approval and the application package is being forwarded to Manila as I type this.
You will have to make the choice that seems most correct for you, and cross you fingers. Good luck with it though!