Stop scaring people. What are you saying?
Immigration at airport in Pakistan (FIA), only stamps passports, they don't SIGN them. What do you mean by signing?
With an immigration visa and COPR, FIA has no legal authority to STOP anyone, unless there is evidence of tampering with any documents.
Most people these days have MRP (computerized passports), so it's a moot point nowadays.
Thousands of women travel and come to Canada to join their husbands, without any issues at borders. Yeah the officials may ask for money/bribe, but if all your documents are in order and issued by the Embassy, there should be no issue at all. those custom and FIA staff are just trying to make money that's all. There is absolutely no requirement to show nikahnama's at airport(s) anywhere in the world. It's just that people are too nervous or scared to give them the right answer. How can anyone not get through, given that almost everyone in Pak knows how to operate the latest smartphones and gadgets? Can't they record audio or video of these airport staff without them knowing??
People should be confident when traveling through Pak's airports, that's all....they only hassle those who are not confident, or very nervous, etc.
All major airlines servicing Pakistan have women and children traveling on them, PIA is nothing special. Believe it or not, it is on PIA aircraft that these so-called men are a problem, on foreign airlines they don't dare to do anything because they know what will happen to them. PIA's employees are always in the news these days, mostly bad. Remember the drunk PIA pilot who got arrested in the UK very recently? God forbid what would have happened if he flew the flight from UK to Pak?
The glory days of PIA are gone. Now there is competition and PIA is almost non-existant,rather, wiped out by its own people/employees.
My advice is, take anything BUT PIA. Because when delays happen, at least other airlines have extra aircraft and you won;t be left without accomodation.