Thank you so much for the update. Ducky was very fortunate to have you in your corner. It sounds like you found her a wonderful place to begin her new life. Well done!
You are a good person for doing this. My non-expert opinion is that she is going to be too stressed to be interested in food, water or grit and that it won't be necessary for a 3 hour ride. Presumably, she goes several hours each night without eating or drinking.
Not sure the best way to...