Sheeh, please think before posting
I'll admit I don't know international law, but it seems obvious to me that this woman was attempting to smuggle these diamonds into Canada. Why else would she try to conceal them? Oh, wait! I've got it! She didn't want them stolen. Yeah, that's it - she was trying to protect them. Yeah, that's it.
The point I (am apparently failing to) make is that this has nothing to do with what you can or cannot be permitted to own. It has everything to do with a person trying to enter into a country without paying the proper import duties on the merchandise she was carrying. Should she be permitted to get away with it? What about the effect that will have on business people who do pay the proper duties on their imported merchandise? Won't that put them at a disadvantage?
Governments do this all the time, and for good reason. If one doesn't like the duties and tariffs a government imposes on goods brought into their country, then one should not travel there.