It is known that some of Isaac Austen's children came to South Africa. Richard came here before Isaac died. Evidence for Richard, James, Martha, and Arthur Elvey Austen can be found in our govt archives.
The evidence for James is "MASTER OF THE SUPREME COURT VERSUS JAMES B AUSTEN IN HIS CAPACITY AS EXECUTOR TESTAMENTARY OF THE ESTATE OF THE LATE RICHARD AUSTEN. ACTION FOR AN ACCOUNT. 1881.
I believe this James may have been Richard's brother as there is a death notice for him in 1889. Richard ,I believe came to SA in 1847 and the archives show a James Austen being associated with a family crest in 1852. Does anyone know whether Isaac's son ,James ,was James Brunswick Austen ?
The only other possibility of the James listed as executor in Richard's estate is possibly a son BUT I only know he had a son Samuel Charles Austen
I also have the family trees that link Isaac Austen to Jane Austen as distant cousins.