Rock Master Publications:
Sublime Climbs - A Guide to the best rock climbing venues in Victoria, Australia.By Kevin Lindorff, Josef Goding & Jarrod Hodgson. Over 700 climbs, 158 phototopos, 36 maps, and 380 pages covering the best of Mt Arapiles, Mt Buffalo and the Grampians $45.00
We went over there last year but didn't do any climbing. The climbing scene in Cambodia is limited in many ways and is still really in the exploration stage. Personally I decided it wasn't worth the extra hassle to try climb.
Her best bet would be to contact Ankor Climbers Net (links below). Their website says there is no access to gear or anything like that in Cambodia. If she contacts the group directly though they might be able to direct her to a guide group or take her out themselves. To my knowledge the links below are the best source of info. These guys run a small climbing gym in Siem Reap and are really enthusiastic and they would undoubtedly be happy to meet any foreign climbers (as they were for us).
One extra thing to be weary of when exploring crags if she manages to get out is the threat of landmines and unexploded ordinance, hence travelling off well trodden paths without a guide is simply not an option (as I'm sure your friend is aware of by now).
I have climbed Thailand (east) and meet some people who had climbed in Cambodia. Do not underestimate the risk of landmines. They were often set "like confetti from the top of rock faces" was what I was told. Having seen and dealt with apo on th Thai Burma border I can tell you the statement is valid. Often 2 or 3 per square metre was found. In particular where they could be tossed from above. Eg rock, road, trail, etc