
If she has been ok up until now I would imagine its not your typical car sickness as I have found that it starts from day 1 although other may say different.
dont Panic....
Dont really understand your explanation of why you think she was drooling ...sorry :)
Try not feeding her and taking short journeys to nice places ie: park have a play then come home
If you search 'car sickness' there have been umpteen threads on this subject for you to browse.
Roni