Looking for Coombe Tuckerman

On the 5th of November 1846 James COOMBE and Elizabeth TUCKERMAN with only some of their children left Plymouth on the "Princess Royal" Emigrant ship.
The Princess Royal captained by Charles Von Zuilecom sailed for four months at sea,they arrived safely at the Port of Adelaide, South Australia on Tuesday the 16th of March 1847.

James & Elizabeth would have been married around 1816c as their first child Harriet was born 1817.
They had 12 children in all...I can't find a birth record of Elizabeth Tuckerman possibly 1800c as James was born 1793 in Altarnun, Cornwall.

Elizabeth Tuckerman is a bit of a mystery...I found her Maiden name on her last two childrens birth records.

Any help would be greatly appreciated!