Received letter stating my wife has to report her income for 2017 from the period when outside Canada for Gst Hstc. However, I already submitted our taxes...

[watermand7541]

Basically, as it says in the question. I submitted our 2017 taxes together, and reported the amounts we had earned from outside Canada. 

I will type the notice, verbatim, in case that helps:

"We cannot calculate the amount of the GST/HSTC you may be entitled to receive for July 2018 to April 2019 without the following information:

-your world income, converted to Canadian dollars, for the period in 2017 before you came to Canada."

Does she need to do another tax return, but on her own? That feels a silly question, but honestly I don't know.

Please get back to me as soon as you are able. I am dying for an answer.

[TurboTaxBrenda1]

Sounds like you need to go back to your return and make sure that you entered the amount you made "world income" in "Canadian dollars". You will need to amend your return

https://turbotax.community.intuit.ca/replies/2647992