Option 1 : You can attempt to dry her by rubbing with many towels on the doormat, or in the porch if you're lucky enough to have one. This works with some breeds, but I find that it doesn't do much for a Barbet's coat and can lead to felting or tanglng.
Option 2 : You can use a "blaster" on her. This was a disaster in Nénu's case until she got her full adult coat at about 3 years old. Before that it turned her into a nightmare ball of wooly felt!! Nowadays it's a possibility and if she is drenched I will use the blaster (which I bought originally for my Newfoundlands) rather than having her hanging around damp in cold weather. Her coat can cope with this occasionally and does not felt too much.
Option 3 : .... and the best option!!! Teach your dog to shake on command! This is not as hard as it sounds. When a dog is wet it will naturally shake the water out of its coat. Every time you see your dog doing this (when out and about by rivers, lakes etc or in the rain) give the commands "Shake!" WHILE THE DOG IS ACTUALLY SHAKING. Eventually the dog will come to associate the command with the action and will shake when YOU want it to.
This is particularly important for working gundogs who should be taught to deliver game from the water BEFORE shaking when YOU give the command to do so! Why? ... because if the dog stops to shake after exiting the water and drops a pricked bird, the bird is likely to run off! In addition, in a competition you will lose marks if the bird is dropped.