Only a decade or so late to the party but thought I would throw some additional info/analysis into the ring for anyone like myself trying to make sense of these Cheetham boys! I have put the following timeline together based on results from ancestry.com and other family history documents:
1794-6 Leonard James Cheetham born
1797-9 James Leonard Cheetham born Lancashire, England
1818 Arrive separately aboard the Isabella (James) and Tottenham (Leonard)
1820 James Marries Elizabeth Ann Taylor at Parramatta.
1840 Either James or Leonard marries Ann Cahill (marriage cert states Leonard)
1841 Leonard Cahill Cheetham born
1846 Either James or Leonard marries Elizabeth Friend (marriage cert states Leonard)
1846 Leonard dies
1858 Birth of Elizabeth Cheetham, illegitimate child of Matilda Murphy (Aboriginal domestic servant) and surviving brother OR Leonard C
1862 Leonard C marries Elizabeth Ann Hawkins
1864 - Elizabeth Taylor dies
1869 Charles Friend charged with shooting with intent to kill Leonard C. Facts state Leonard C is the son of James who married Charles mother approx. 25 years prior (matches 1846 date - no mention of her current whereabouts)
1871 James dies
1873 - Ann Cahill dies (death index lists husband as James and Leonard C child)
1873 - Elizabeth Friend also reported as passing (under surname Cheetham) however particulars match that of Ann Cahill (supported only by grave index). A separate death index (undated) lists Robert as spouse and Charles Friend as child.
1876 Leonard C dies
1881 (Illegitimate) Elizabeth Cheetham marries James Cowley
1891 Matilda Murphy dies
1898 (Illegitimate) Elizabeth Cheetham dies
As indicated, there are several questions which remain unanswered. My suspicions are:
1. James married Elizabeth Taylor
2. Leonard married Ann Cahill and fathered Leonard Cahill. Upon Leonard's death, James raised Leonard C as his own. Alternatively, James posed as Leonard to marry Ann and is indeed Leonard C's father.
3. James married Elizabeth Friend, again posing as Leonard.
4. Leonard Cahill is the father of the illegitimate Elizabeth Cheetham given both he and Matilda Murphy were both aged approx 17 at the time. Alternatively, James fathered her in his mid-50's.
The mystery of whether Ann Cahill or Elizabeth Friend died in 1873 (or both) is one I'm still working on...