Thanks for answering my question, Newfy.
With your help, I now have Amelia, Edward, George, Herbert, Fanny, Son #4, Titus, Whitlam, Mary, Helen, Ada.
I know from another source that there was a son called Whitlam [1846-1851]. If the 1851 name really is William, then we have Son #4, but if it is Whitlam, then we still lack the name of 1 son. Incidentally, Whitlam was their mother's maiden name. Odd that they didn't call the first son by that name.
Thanks
Dolly