As my good friend and Ayn Rand disciple Sterling Archer might say, "phrasing". 'Ill-considered' might be slightly more descriptive.
Yes, technically the GOP is right. Tammy Duckworth used to stand up for veterans. She stopped during her service in the Army.
As a commissioned officer in the Army Reserve, Duckworth chose Helicopter Pilot because it was one of the few combat roles open to women. On November 12th, 2004 the UH-60 she was co-piloting was hit by a Rocket Propelled Grenade. She became the war's first female double-amputee.
So yes, technically she doesn't stand up for veterans. (I can hear a certain Presidential Candidate saying: 'I like soldiers who don't get hit by RPG's'.)