** SECOND IN A SERIES OF SIX ** Ashtyn Gardner, 2, from Mobile, Ala., gets her foot caught on a walker belonging to another child, left, and begins to lose her balance as she is greeted by Sunny, one of the presidential dogs, as she is held on a leash by first lady Michelle Obama, as children of military families participate in a holiday arts and crafts event in the State Dining Room at the White House in Washington, Wednesday, Dec. 4, 2013. (AP Photo/Charles Dharapak)