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