In fact, I know that Wei Ling would have been happy to serve NS. She likes the physical exercise, and fitness training, and also quite gung ho. I am sure she would have been good with weapons.
I suspect that the issue of NS for women was raised by the Mexicans who came to form the SAF. They have NS for women themselves in their own country. And when the PAP wants to harp about total defense and what not, for sure you have to include training. In Israel, most of the instructors in their school of armour, i.e. driving and gunnery instructors, and women conscripts. Why the PAP did not adopt their recommendations for the women to be included in NS must have come from Gecko. Gecko wants women to have rights, but not be burdened with the duty that comes with that.