lingqi is the combination of the second characters of Shangqi and Xialing's names, and I have this vague inkling that the compounding of these two concepts (qi-lifeforce and ling-spirituality) have ties to taichi as a martial arts form and so obviously ties them to their mother, but I really don't know enough about taichi to really say anything intelligent about it. But it's clear whoever came up with the specific Chinese characters for these characters' names have put a lot of thoughts into it.