There is an XPT service that runs Sydney to Bathurst and return daily as well as several trains that run to Lithgow and connect with a bus to Bathurst.
The link below is to Train and bus timetables Sydney to Bathurst
The link below is the Southern NSW any service that goes to Cootamundra has a bus link to Bathurst however I think this takes all day to get from Melbourne to Bathurst. There is also a link from Canberra to Cootamundra and then by rail bus to Bathurst.
Indian Pacific stops at Bathurst (last stop before Sydney) if you have the time and money for a bit of luxury along the journey. The stop is not mentioned on the web page but I did check with the Ticket office here in Bathurst ,you just have to mention it when booking.
Rex Airline run a twice a day service between Sydney and Bathurst
It is only a 2 and half to 3 hour drive from Sydney to Bathurst (if you don’t stop at any quilt shops on the way) and perhaps if 4 ladies got together at Sydney Airport you could hire a car, split the costs and you would have a car for the weekend.
There is also a daily bus service between Sydney and Bathurst
This information can also be found in the files section of the Retreat Yahoo Group.