....
She is not working for her parents because we've been living together in another city in China until a week ago. Do you think it will help if she returns to her parents and works for them now?
Well, that would not hurt, but I would be reluctant to see you two living in separate cities just so she can work for her parents. Particularly if it comes out in the TRV process that the employment is very recent. It might not be seen as a particularly compelling reason for her to return home from Canada.
I should point out that I have read here of some who appear to have weak TRV applications being honest with the IRCC and saying they want to be together in Canada pending PR application decision and they have been given TRVs. In other, similar, cases, TRVs have been denied. So no particular outcome is assured.
With any luck, others here will have more guidance. Things seem to have changed somewhat in light of the "new policy" for TRVs for spousal PR applicants. But, again, for some, not much has changed.
I should also point out that I am ill-qualified to advise in this area. My wife and I applied 3 times for TRV for her. Denied each time. The last application went in about a month before the "new policy" announcement. So I can hardly claim a record of success.