AS can be seen on the PECK of Taita tree at this link -

George Avery was born in Staplehurst, Cranbrook, Kent in 1824.
When aged 16, he arrived in New Zealand on the BOLTON in 1840 with his parents Thomas and Elizabeth Ann (nee Dapson) Avery and 7 siblings:
Harriett Avery b.1822 married Dr Mannering
Charles Avery b.1826 never married
Ann Avery b.1828 married Peter Humle
Mary Avery b.1830 married Mason Hill
Sarah Avery b.1832 - no further info
Ellen Avery b.1834 married Charles Saywell
Stephen Avery b.1839 married Eliza Hooper and Marion Stewart and Sarah Jane Collard

George married Charlotte Tandy in the Hutt Valley, New Zealand and they had 17 children ...
George and Charlotte are buried in the Christ Church Taita Cemetery

I only have 4 of George and Charlottes children on my tree at this time - they are:
Charles Avery b.1851 married Jane Hirst
George Avery b.1852 married Sarah Scrimshaw
Thomas Avery b.1858 married Annie Hall
Stephen Avery b.1854 married Jane Hirst (daughter of the above Jane Hirst's brother)

Can you please help with who the other 13 children were?