How long people can live?

One day my 8-years old daughter was chatting with me about how long people can live. She asked simple straight questions: "When my grandmother will die?", "When mother will die?".
And later he addresses the same question to me: "Father, when you will die?"
And I replied: "Well, I do not plan to die so far..."
"What???"
"I do not plan to die, I will probably live over 600-900 years if you need some number"
"But people don't live so long!" - she wondered.
"Who told you this?"
"Hmm..." - she was puzzled, "I have seen a granny 94 years old, but I have never seen anyone older than this age"
Children are not that stubborn as us, adults, and I went forward.
"Well, since the beginning of the humanity, humans lived 600-900 years, and this is recorded in the Bible. For example, Noah, the hero who saved all life of earth during the Great Flood, was 600 years old when flood happened, and later he lived more and died and at the age of 950 years. Now, I guess, the is a lot of people living who are really old, but we don't know about them, and they don't like to show their age in wide public."
"Yes, I know!", suddenly my daughter screamed. "One of my classmate is from the aboriginal tribe (in Taiwan) and she told that there is one granny in their tribe who is 800 years old."
"Why didn't you tell me this before?" - I asked.
"I thought nobody will believe me, because nobody did really believed that girl"
"Did that girl told you how did she know about the age of the old lady?"
"She told that everyone in the tribe knows that granny is 800 years old and she asked old lady by herself and granny confirmed that she is 800 years old... Do you think this can be true?"
"Yes" I said, "The is no reason for me to doubt this".
"Hmm..." my daughter said, "I was also wondering why would the old granny lie to a little girl?..."