Is wife a US citizen? Resident Alien?

She's a permanent resident.

Effective when?

May 22, 2020 to May 22, 2030

She's a dual status. She can file joint return with husband, but that means she's electing to pay US tax on her worldwide income for 2020.

Or she can file a separate dual status return. Only her US source income would be subject to US tax in this case.

First how they can file joint returns when her husband is a full-year US resident while she was only US resident since 5/22/20 ? How can I answer residency in ProSeries Basic  for both of them ?

I think It's appropriate to file married separately. 

But either way, I think she gets to report both of her Canada and US income ? Her tax paid in Canada has foreign tax credit on US tax return.

What do you think ?

Thank you 

I think you need more help than you can get from strangers on the internet.

The 1040NR instructions and IRS Publication 519 US Tax Guide for Aliens are very good resources.

Anyone else can help ???