This is the dorsal view of the abdomen. The holes are probably for breathing purposes. Note the surface covered in minute hairs.
The spinnerets have produced a strand of silk even though she is stationary. She has a "lifeline" that keeps her in contact with her web should any catastrophe strike.
This species has a broad distribution as can be seen from their distribution map. Thanks to Graham for the info.
Harvey, M. S., Austin, A. D., Adams, M. 2007. The systematics and biology of the spider genus Nephila (Araneae: Nephilidae) of the Australiasian region. Invertebrate Systematics, 21: 407-451.