If she is good in the car, then I wouldn't worry too much about it. At 10 weeks, she will need her bathroom breaks, but I am sure you already knew that. If you don't want to stop that much put her in her crate and she will be fine.
I got Billy at 9 weeks and on his first car ride, he got sick...twice, but since then he is a dreamy passenger.
I got Billy at 9 weeks and on his first car ride, he got sick...twice, but since then he is a dreamy passenger.