What kind of child was Helen Keller before her illness in The Story of My Life?

Before her illness Helen Keller was a precocious and active toddler. 

From a young age, Helen Keller showed signs of intelligence and spunk.  She says that as the firstborn, “I came, I saw, I conquered.”  Even as a very young baby, she was intelligent and dominating. 

I am told that while I was still in long dresses I showed many signs of an eager, self-asserting disposition. Everything that I saw other people do I insisted upon imitating. At six months I could pipe out "How d'ye," and one day I attracted every one's attention by saying "Tea, tea, tea" quite plainly. (Ch. 1) 

Little Helen was obviously very smart.  The fact that she was able to learn language so young turned out to be both helpful and harmful.  She knew some words, but she also maintained the babyish ones like “wah-wah” until she had Anne Sullivan to teach her the correct ones.  

She walked at a year old.  Helen’s illness would hit before she was two. 

Then, in the dreary month of February, came the illness which closed my eyes and ears and plunged me into the unconsciousness of a new-born baby. They called it acute congestion of the stomach and brain. The doctor thought I could not live. (Ch. 1) 

Helen did live, and the fever left one day as quickly as it had come.  However, she was left without the ability to see or hear.  Little Helen gradually got used to “silence and darkness.”  Doctors did not know if she would ever be able to see or hear again.  She never did. 

Since the family could not communicate with Helen, they had to find her a teacher.  Anne Sullivan came and replaced Helen’s baby sounds with real words when Helen was six years old.  Helen was intelligent enough to learn several words in one day, starting with “water.”  Anne Sullivan spelled words into her hand since she could not see the words or hear them.