It must be confusing for your daughter to cope with another new language: German. Even if she is in an English school, the language she hears around her will be totally different. And even English is spoken differently by people in Germany, compared to the English she had heard spoken in India. It is not surprising that she feels that her school tasks are difficult.
Children songs in German must be available. Maybe listening to them will help her a little. The system of learning answers by heart leads to no new information or knowledge. It is much better to understand what one is doing. Even if the process is slow, understanding what is written is very important. She may as well pick up the right kind of learning habits.
Since your daughter has been a little different from the very beginning, it is better not to push her to achieve a specific goal. You should also consult the School Psychologist (there is likely to be one attached to the school) and explain the child's health history and ask for advice on how best to handle the situation.
Start from your child's strengths and interests, instead of focussing on what she cannot do. The DoctorNDTV archives also have a couple of articles on Autism, which may help you, even if your child is not autistic. Your child must also be missing her friends. Try and find an activity that also involves other children, in which she can participate. But do this gradually and without pressure to get to some point. All the best.