Thanks for your suggestions.
Here is what I have on the families of Richard REES:
Richard Rees
Born: c.1811 at Llanidloes, Montgomeryshire, Wales.
Parents: Jenkin and Betty REES.
Siblings: 4 unknown brothers, 3 sisters - Bessy, Peggy, Martha.
Religion: Protestant.
Language: Welsh.
Description: 5 foot 5 inches, brown hair, blue eyes.
Employment: Agricultural labourer, bullock driver, farmer
Married: Mary, had two unknown children.
Convict Years
3 Jan 1841 - convicted at Breconshire Quarter Sessions for stealing two sheep from his employer, John MORGAN. Sentenced to 10 years transportation.
6 Jun 1841 - census night aboard convict hulk Warrior, Woolwich Dockyard, Kent.
30 Aug 1841 - transported to Van Diemen's Land from Sheerness, Kent, aboard Barossa.
13 Jan 1842 - arrived Van Diemen's Land, employed at Bridgewater.
16 Jan 1849 - conditional pardon granted.
8 Jan 1850 - left Launceston aboard Halcyon, a free man.
18 Jan 1850 - arrived at Port Adelaide.
Second marriage
12 Jun 1852 - at Gawler, SA, to Ellis "Alice" HARDING, formerly SARGENT nee PACKHAM. Ellis is a 46 years old widow. No children from this marriage.
21 Oct 1863 - Ellis REES dies at Butcher's Gap, SA. Buried at Sprinfield.
Third marriage
19 Feb 1864 - at Kapunda, SA, to Christiana BLAKE nee McFEAT. Christiana is a 34 year old widow.
21 Jun 1865 - Martha REES born. Martha marries Albert RHYMER and died 13 Jun 1936.
9 Apr 1868 - David REES born at Marrabel, SA. (my gt-gt-grandfather)
16 Feb 1872 - Richard REES jnr. born at Springfield, SA.
14 Jun 1874 - Richard REES jnr. dies at Marrabel, SA.
9 Mar 1879 - Richard REES snr. dies at Butchers Gap, SA. buried at Springfield.
9 Dec 1918 - Christiana REES dies at Marrabel, SA. buried at Pancharpoo.
I don't have any details of the children that Ellis or Christiana brought into the household when they married Richard, so they would gratefully be welcome.
Cheers
Nudge