TurboTax keeps saying we owe upwards of 2000 on our joint tax return for my wife's salary. She is a non-citizen, and was a non-resident for 2017. What should I do?

(We are in Alberta, Canada) My wife earned an amount that was considered low-income in her country, and thus did not pay taxes according to tax law there. 

We were BOTH non-residents for 2017, however, I am a Canadian citizen, while she is not. We returned near the end of the year to live in Canada. She became a permanent resident upon entry, but was not prior to that. I am now attempting to fill out a joint return for 2017 for child benefit purposes. When I report my wife's income in her country, and the fact that she paid no taxes on that amount, the return suddenly comes out as saying we OWE Canada more than 2000 dollars.  Obviously this is unacceptable as she is non-citizen and wasn't even a permanent resident at the time she earned that money so she should have no tax obligations to Canada for that.

I understand that as a Canadian citizen I need to report my earnings abroad even though I was a non-resident during that time for tax credit purposes, but should we leave my wife's earnings as zero, considering she has no obligation to report those earnings as a non-citizen/non-permanent resident at the time she was earning that money? 

Or should we file separately for this tax year? I don't like that though, as we are both low income at the moment and would greatly appreciate the increased benefits filing as a family would entitle us to.

How can I fix this? Thank you for your help and patience ahead of time. I am quite bad at this, but want to learn to be better.