A PR can't be made inadmissible to Canada. Not sure where you are getting this from.immigrationteacher said:Most of you are too harsh on Darshana. The max penalty for her mistake is inadmissibility and perhaps (not for sure) loss of PR.
Worst possible case here if she proceeds with trying to sponsor her undeclared husband, is that CIC revokes her PR due to misrepresentation. Though I agree also this is hardly likely as other cases show CIC doesn't usually start revocation process for non-declaration, they seem to view not being able to sponsor your family member as punishment enough.
She may not need a lawyer at all. If she just accepts what she did and that she can never sponsor her husband, she can voluntarily renounce her PR status, leave Canada, and start as soon as possible to re-qualify under one of the current economic streams only this time including her husband in the app.All she needs is a tenacious lawyer to represent her. We can revisit this forum and stay in touch with Darshana to see what happens.
Or she can choose to hire a lawyer to file her husband's PR app and go through the appeals process after that's rejected, if she really fees she has some extenuating circumstance (though doesn't seem likely). This will involve years of time and possibly thousands of dollars if she wants a good lawyer, and will most likely still result in eventual rejection. However it's up to OP how they want to proceed here.