Sgt. Betty Zavala is a U.S. citizen who has been in the U.S. Army for 8 years. She is stationed in Italy and is married to an Italian citizen who has never lived in the United States. Their 3-year-old daughter was born in Italy. Sgt. Zavala has also adopted her husband's son, who lives with them. The Zavalas provide total support for the two children. How many dependents can Sgt. Zavala claim on a joint return?