Catherine Neill, Eleanor Palmer, Henry Neill

Hi I am searching for information on,Catherine Neill who was born in Dublin in 1836...as a twin. Her twin died from burns in a fire aged about 6. so around 1841. Her father, Henry Neill was a sergeant in the Army and died when she was about 2., so around late 1830s.  Her mother Eleanor Palmer died when Catherine was about 8 - 12. so around 1842 -8 so she was an orphan. a lady taught her to read and write but died when Catherine was 17 so she  emigrated to Australia in 1853 and married John Prewett.

I have not been able to find any records of her, her parents  and twins births or deaths. as these dates are before 1850s. Catherine died in Australia aged 40 in 1876

Thankyou.