Her oldest son Track deploys for Iraq on 09/11. Not to be cynical, but she's got skin in the game. Gives her more credibility on the WOT than the rest of the field combined.
IIRC both McCain and Biden have their children serving, so its not unique.
Biden's elder son, Beau, had been a partner in the Wilmington law firm of Bifferato, Gentilotti, Biden & Balick, LLC until he was elected Delaware Attorney General in 2006. Beau is a captain in the Delaware Army National Guard, where he serves in the Judge Advocate General's (JAG) Corps. He is set to be deployed to Iraq in October 2008.[8] Biden's younger son, Hunter, works as a lawyer in Washington, D.C., serves on the board of directors of Amtrak, and previously worked in the Commerce Department.
McCain's son has served, and he has another at Annapolis.
I stand corrected, thanks Agricola. Wonder why they haven't made a bigger deal about that?