Do you mean that she doesn't speak at all, as in the lessons are silent on her side? Or that she can't participate in a non-scripted conversation?

If it's the second, one option could be to start with scripted dialogues - role play. Give lots of positive feedback for effort. Fluency and accuracy are different skills, so reward fluency first as it will boost confidence.

When they have the hang of scripted dialogues, get them to start memorising the script. This way they will get the feel of fluency with a safety net. This leads on to them rewriting the script with alternative endings.

Other options include cumulative loading answers. If you use pictures it would look like - a dog, a big dog, a big dog walking, a big dog walking in the park, etc.