If you do decide to try this method, do be careful not to confuse ambient humidity with the humidity that is trapped within mom's coils (humidity in the enclosure could be around 70% but the pocket of air surrounding the eggs within mom's coils will be significantly higher). There's a tendency for people who are trying maternal incubation for the first time to try to turn their female's enclosure into an incubator. If you're going to try the maternal route, you definitely don't want to tamper with the temps/humidity in her enclosure UNLESS you're having trouble maintaining the right temps and suitable humidity for ball pythons.