There are a number of things you can do to cure motion sickness.
First, be aware some puppies just grow out of it as they mature.
But to help what you can do is to feed her in the car WHILE THE CAR IS STATIONERY! Get her used to being in the car without it moving. Also just let her sit in the car and then get out again. Do both these exercises without taking her for a ride in the car. Repeat several times over for the next few days before actually taking her in the car. Some dogs are afraid of the car, thus causing motion sickness, this will help her get used to just being in the car.
Also Bach's Rescue Remedy is really good, it's a natural product, but do make sure you ask for the correct dosage. It works on the weight of the dog as to how many drops you give them. It will calm her down but not sedate her.
Your vet also will have motion sickness medication. I had to use this with a dog I once owned, only for a short time, when she was a puppy then she out grew her motion sickness.
Plus when you take her in the car, just make it a VERY short journey at first, round the block or just down the road. Don't take her on long car journeys and by long I mean anything over a few minutes, until she's over her motion sickness.