My mom says prey animals have to have short memories and she's right. In the wild, ducks would be fighting for their lives and getting traumatized by every little unpleasant experience would be a detriment to their survival. A visitor once dropped a 1/4 sheet of OSB on one of my ducklings. It broke off a toenail and gouged his leg a little. He was pretty upset and wouldn't come near me the rest of the afternoon but he got over it. Just make sure you give her something soft to lay on and keep her carrier/box dark and she'll be fine.
I just drove my duck to the vet for the first time yesterday. She was fine!! Seemed to take the whole experience very well. She was super excited though when we got out into the back yard and saw Jade!! They duck chatted like I have never seen!! lol
I haven't taken everyone to the vet yet, but Sieben, Neun, and Vier have been okay with it. I put them in a coated wire dog crate. They could see out, and seemed interested but not totally overwhelmed by the sights and sounds. I talked to them as we drove (it's a bit of a drive), and they seemed a little nervous but not scared. When we got to the vet, in the examining room when there was a wait, they have dozed off.