Welcome aboard, Ellen! It is less than a month until your family gets to set sail on the Disney Magic for an amazing cruise to some of the most spectacular European ports! I was fortunate enough to enjoy some of those same unique ports last summer with Disney Cruise Line, and I can tell you from experience that you are in for the trip of a lifetime!
Because I don't know of which country you are a citizen, I cannot give you specifics on travel documents required, however, I believe from your question that you are not a U.S. Citizen. U.S. citizens are required to have a valid U.S. passport for Disney Cruise Line's European sailings. Since I'm guessing you are a citizen of a European country, there are different requirements.
Please take a look at the
European Travel Document Requirements on the Disney Cruise Line website, where you'll see more details. You'll want to contact your travel agent or government agency, embassy or consulate to verify which documents you may need to sail. You will certainly need a valid passport from your home country, but there may be other visa requirements based on your nationality, so please check into those as soon as possible, since it is only a few weeks from your sail date.
Have a wonderful cruise, Ellen!