Giving birth in Canada will also give the child Canadian citizenship, something they otherwise wouldn't have as their mother is just a PR (and I assume will lose her PR before naturalizing in Canada).
While you 2 may never plan to live in Canada, it's impossible to say what the child will want 20, 30 etc years from now.
For example I'm currently in a long distance relationship and it'd be awesome for us if my gf could have moved here for a bit and lived with me.
The Canadian immigration process is also headache inducing, so the opportunity to get a "free" passport in a first world country is a nice luxury to have
