Contacts of spouses with families, which they enter, they begin with the problem of the name and the way of addressing oneself. The woman, changing her marital status, takes the surname of her husband, he may, however, keep his maiden name for personal or professional reasons (which are always given in the documents anyway), combining them with her husband's surname (Anna Kowalska–Nowak). Let's add, that in Poland a woman may remain with her maiden name, not taking her husband's surname, alternatively the man may take the wife's name.
How to address members of a new family? Nowadays, young people have much more choice in this regard than before, when the parents-in-law were only called "mother" and "father". It all depends on the age of the parents, familiarity, lifestyle. If the in-laws already have a son-in-law or a daughter-in-law, best to adapt to the adopted forms.