I'm just curious about this, I hope you don't mind me asking a bit more.

Did he sign for her to get a visa, or PR status?

For a visa I think they don't check status as he's just writing a letter saying "She can come visit me in Canada". Then she's going to turn around and get him a visa too in the same way?

It should be impossible for him to sponsor her for PR status, because it takes years and goes through several reviews and his PR number is a required field.

Did you know that people here on a student visa that bring their kids with them can get CCB? And because they're not earning money here, on their taxes in Canada they show as $0 income (but have income back home or support from home) they get the maximums.

My wife's friend was doing that a few years. I was like "WTF, her family is wealthy and her ex husband pays child support." but since that's all in her home country, CCB pays big.