The 41 black and white photos taken by Rupert Potter include one believed to be of his daughter sitting in the porch of Broad Leys house in 1909.
The image was captured by Lake Windermere at the time she was working on The Tale of Ginger and Pickles.
David Brookes from 1818 Auctioneers said the collection was sold to an online buyer in Canada for £1,000.
Mr Potter, a keen amateur photographer, had some of his work exhibited at The National Portrait Gallery and the Victoria and Albert Museum in London.
The photos were sold on Monday by an anonymous vendor whose family once worked for Beatrix Potter's mother in Windermere.
A collection of photographs taken by Beatrix Potter's father have been sold at auction.