Information on Robert Stewart and Mary Neilorneill

ROBERT STEWART B.abt 1807 Stirling Scotland. M 1840 Maitland NSW Australia to MARY NEIL or NEILL B.abt 1817 in
County Kerry Ireland

I am after any details of the life of Robert @ Mary before they came to Australia. The only info I have is
the following;
Robert was convicted in the Glasgow Judiciary Court 7th April 1830 on a charge of stealing butter and was
sentenced to 7 years transportation. He arrived in Australia 22nd March 1831.
Mary was convicted at the Kerry Summer Assizes (I believe in Tralee) in 1836 on a charge of stealing money
and was sentenced to 7 years transportation. She arrived in Australia on 25 December 1837.
Robert was on board the ship "Burrell" and Mary was on the "Sir Charles Forbes".
I know nothing about their lives in Scotland and Ireland before their arrival in Australia and this has caused a huge gap in the family tree.
I would be grateful for any help.

Thank You
Lindsay