In this story covering her swearing in, the Times' Peter Baker writes
"Arguably, Justice Kagan made a mark from the moment she took the oaths on Saturday. She is the third woman on the current court, joining Justices Ruth Bader Ginsburg and Sonia Sotomayor. She is also the fifth justice born after World War II, making that group a majority, and she brings down the average age on the court to 64, from nearly 69. And she is the first person since William H. Rehnquist, 38 years ago, to join the court without experience as a judge.
If her installation added diversity in some ways, though, it reinforced the court’s lack of it in other areas. Her addition means the court now includes neither Protestants nor anyone without an Ivy League background. Justice Kagan joins two other Jewish justices and six Catholics. She is the sixth justice to have studied at Harvard Law School (although Justice Ginsburg later transferred to and graduated from Columbia Law School); the other three graduated from Yale Law School. And she is the fourth justice to have grown up in New York City."