Answer:
I don´t think there are any black characters in her novels, there was a mulatto (sp?) character in Sandition. When someone is said to be very brown, it usually means that they are tanned.
I kindly point out that these series of questions on Jane Austen are based on scientific research, and you answering with 'I don't think' does not do justice to the research. Now that I have raised this issue I expect anyone interested to go and reread their Austen books. Page one of Northanger Abbey for instance, immediately informs us about Miss Morlands colour/ complexion. Miss Lamb from Sanditon is described as a half-mulatto from the West Indies. Mr. Elton, black, spruce and smiling is from Emma. Absolutely plain, black and plain, is from Mansfield Park. His beautiful sister Mary is brown, with a lively black eye.