Robacrobac
I checked a very old bdm index for NSW and the child Ellen McEVOY with parents Richard & Ellen born 1852 was christened in the Roman catholic church, Bathurst, Kelso, St. Michaels
The record listed is her christening record and not her actual birth record
Bathurst is near Orange so very likely this is your Ellen
Have checked some immigration indexes and the only Richard McEVOY I found arrived in 1856.
They are not listed on the bounty immigrant index
They may have arrived in any state
The NSW, victorian and queensland bdm indexes are online and there is limited SA indexes up to 1850
If you need the web address for these sites let me know but you can find them doing a google search
The NSW ones are under the state records NSW site
Their arrival could also be under a wrong spelling of surname
Liz