Congratulations on having such an intelligent little girl. Her brain and understanding are obviously well developed. She wasn't babbling gibberish. Just sometimes language formation in the brain far exceeds the development of the muscles and nerves required to say the words. Her brain knows the words. She wasn't just repeating sounds. She was relaying important information that her brain had processed. This was not mimickry. It was conversation. Try her on reading a book. It should be easy for her in no time at all.