Which phrase is correct:
This is the Brown family vs This is the BrownS family? (from the surname BROWN)
This is the Ivanov family vs This is the IvanovS family? (from the surname Ivanov)
Or both variants are correct when we are talking about the whole family? This question has arosen because in some student's books I saw one variant, in other ones - another variant.
Thank you in advance for your answers and explanations.