You think so??? Yes she can, and no she should not. How will either of you feel if she falls and has a miscarriage? Even if the miscarriage has nothing to do with the fall, you will always wonder if she would have had a miscarriage if she did not fall. Enjoy her pregnancy...There will be plenty of time for rock climbing later.
No. Any potentially dangerous exercise/activity is contraindicated in pregnancy. Pregnant women have poor coordination of their movements as a result of pregnancy hormones and are more prone to falls and injury than non-regnant women. Avoid rock-climbing, all contact sports and any strenuous exercise or heavy lifting in pregnancy! try swimming, stationary bike, brisk walking/treadmill in a/c spaces.