JOEJOY Elevated Dog Car Seat for Small/Medium Dogs up to 35 lbs, Memory Foam Booster Seat with Detachable Washable Cover, Travel-Safe Car Bed with Safety Belts & Storage Pockets, Grey

I had a front amputee dog. I just used a buckle collar and not a vest. He lived for 10 years as a tripod and never needed additional support of any kind. Since she is small, you could get a bucket type car seat similar to this Just remember the front legs are the shock absorbers and the back for push power. So she will use her back legs to get up and power forward. Her front leg will be what absorbs the shock on a land. If you can lift her down from a high place, it is easier on her remaining front. You will find her front leg will be larger amd stronger than a dog of the same size woth two fronts.