As per IRCC, there's no such mandatory requirement. Women can keep their maiden names after marriage.
As per Pakistani Law, women MUST change their legal guardian's name in CNIC/Passport AFTER marriage OR divorce.
Your Govt. ID (such as CNIC & Passport) cannot be renewed if you are married and you have not applied for modification of CNIC After marriage.
For Legal Guardians:
Note: Most applicants don't face any issue unless until they apply for renewal of documents inside Pakistan or Pakistani consulates/embassies/highcommissions.