Hi there,
Have you confirmed that the 1900 marriage registered in the Bombala district for Ada A HOLMES and William SMITH is definitely your lass?
The NSW BDM has that marriage indexed as #8326. An official transcription of that mc will give you the family history information re parents of the bride and groom, as well as details about both Ada and William (age, occupation, bachelor/widower/divorcee and spinster/widow/divorcee etc). With the popularity of the surname SMITH, the groom’s occupation becomes one of the significant pieces of info to help find the couple.
http://www.bdm.nsw.gov.au/familyHistory/familyHistory.htm I have looked at the NSW ER 1903 EDEN-MONARO, polling at Bombala.
There is a William Edward SMITH, of Bombala, a drover. I cannot find Ada enrolled there at that time, HOWEVER, she needed to be aged 21 to be eligible to enrol, AND it was not compulsory to enrol. Also, there’s no real way to draw the conclusion that the William Edward SMITH I am listing here was the chap married to your lass, based only on this Electoral Roll entry.
Cheers, JM