The Llewelyn Davies boys inspired which character?

The Davies boys were the inspiration for the stories of Peter Pan by J. M. Barrie, in which several of the characters were named after them. They were the sons of Sylvia (1866–1910) and Arthur Llewelyn Davies (1863–1907).
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Barrie became the boys' unofficial guardian following the deaths of their parents, and they were publicly associated with Barrie and Peter Pan for the rest of their lives.
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They were:
* George (1893–1915)
* John 'Jack' (1894–1959)
* Peter (1897–1960)
* Michael (1900–1921)
* Nicholas 'Nico' (1903–1980)