why can't she leave and then apply in the correct manner from outside of Poland?
I wonder that too?
So if she leaves, will she be let back in the country?
If the authorities don't know she is staying without proper papers. She should leave Poland and get the proper papers, then she can go back to Poland.
They both want to leave Poland and make a life in another country and get married
If you get married to a Polish man I guess you have the right to stay in Poland forever if you want to.
But you should only get married if you really love him, and wants to be with him for the rest of your life.