Z had been coming along well with her communication. Not all of the words were correct (she used "boom" for food), but we understood what she was trying to say for the most part. She could say dada, hi, and a few others. Now she seems to have no words. She still understands us, and she is talking but it's all unintelligible and babbling. I am worried that she isn't using the words that she had anymore. Has anyone had any experience with this? With her 15 month appt coming up, I was wondering how concerned I should be.