I would do as suggested. Sometimes the dog behaves better with out the owner, maybe try that?
Also to help in the future I would bring her there often, as often as possible just to get weighed & petted & walk into the exam rooms. Check w/ your vet & see what times of day they are not using the exam rooms or what is their slowest part of the day. I am sure they will agree to it. Maybe if it just the syringe than have the Dr. give you a couple (without needles or oral syringes that look the same) & bring them home w/ you. Show them to your dog & touch them to your dog. get her used to them. Ignore or give a stern "NO" everytime she mis-behaves then PRAISE with everything youve got when she behaves properly.
Good luck. I worked as a vet tech for years & those techniques seem to help most dogs the owner has to be very patient & has to work constantly on it. I wish the best of luck!