Is jack and rose real because my older sister says so?

Are they real because I'm a big fan on the Titanic and I must know.I've been watching the movie a lot and wandering if Jack Dawson and Rose Dawson Calvert even exist.The Titanic is famous but are the people real because my sister and I study the Titanic together and we want to know.I did a lot of research and kept looking for answers and it said that they were made up thats soooooooooooo crazy