Since you indicate that your daughter has a well-defined clinical syndrome, I assume that you have already taken her to a speech and language clinic for an evaluation. If so, you were probably given some suggestions as to how to help her. I may not be able to add too much but will try.
The condition your daughter has is generally known as developmental apraxia of speech, often abbreviated as DAS. Although it is known to be associated with a brain disorder, nobody knows exactly what causes it or exactly what it is in the brain that doesn’t work right. Different prenatal and birth experiences have been implicated, but many children with difficult birth histories do not develop the difficulty. Furthermore, many children with DAS experienced nothing unusual in their birth histories.
Children with this disorder do not seem to be able to control the muscles used in the production of speech sounds. They might be able to say a word, or part of a word, correctly one minute and be unable to do so 10 minutes later. The affected children are aware of this and often become anxious about trying to talk, which, of course, only makes things worse.
Most speech and language specialists think that DAS is a type of speech disorder that should receive professional treatment at a very early age. You do not mention your daughter’s age, but if she is at least 2 and has a DAS diagnosis she should probably be in intensive speech therapy (two or maybe three times a week). Apraxic children generally learn to speak satisfactorily, but it is often a long, hard struggle.
As to what you can do at home, I would say that one of the main things is to avoid increasing your daughter’s anxiety about her speech. If you can understand her at all, accept what she says without asking her to repeat herself. Avoid putting her “on stage” by demonstrating achievements or improvements to grandparents or friends. Try to be supportive and patient.
Our parenting advice is given as suggestions only. We recommend you also consult your healthcare provider, and urge you to contact them immediately if your question is urgent or about a medical condition.