She needs the new iPad because she doesn’t have electricity or BlackBerry coverage in the wake of Hurricane Irene. Blumenthal is a private citizen without a security clearance but also a close confidant of Clinton’s. The email is one of 15 between Clinton and Blumenthal that Clinton did not give to the State Department, but Blumenthal did. (The Associated Press, 6/25/2015)
Clinton began using an iPad in addition to her BlackBerry in 2010, including for work emails. (Hillaryclinton.com, 7/13/2015) Presumably, the iPad she uses in Paris and afterwards is not secured or approved by government security officials, just like her previous devices.