I see no reason as to why women shouldn't be allowed to cough. There is no need for any restrictions on coughing. What's the motive behind this question, exactly? I can only assume that women not coughing somehow increases their femininity, or that women not coughing is a religious tradition or idea. Please tell me that this question has a real motive, instead of just asking a ridiculous question.
Even people with vaginas have to cough.