My 15 month old is sick if I go out in the car within 2 hours of her breakfast. It's just mornings and never sick at home. Is it just travel sickness?

It may be. If she wakes up with congestion, she may have a lot of mucous in her stomach. That may not go well with milk first thing in the morning. You may try giving her light foods (dry cereal, toast) and clear fluids first to see if that stays down. The other possible concern is if it is anxiety related- is she on the way to day care? See your doctor and make sure it is not something physical first.