20/20: Mothers' Work/The Kiss of Death/Playing Mary Poppins

Elizabeth Vargas studies women like herself who try to balance family and career. She questions why the cost of day care is so high and why maternity leave is not paid for by the government. Then, the story of a high school girl who was stabbed and killed by her boyfriend, a star football player. Finally, a look at the new Broadway musical version of "Mary Poppins."