I searched both google and bing.
It looks like it’s safe for our baby as she will be 3 months old (source: Indusladies.com). For new born, it’s almost a no-no (source: about.com). One factor, I saw from about.com and kidsgrowth.com, is the air quality in airplanes and the potential to exposed her to virus. Quote kidsgrowth:
The air in planes is not filtered and recirculates throughout the cabin. All the viruses and other nasty germs circulating through the cabin will increases your infant’s chances of getting an infection.
We also searched Chinese search site baidu.com keywords “新生儿 坐飞机”. And we got similar results, such as this one from pcbaby.
Considering all the risk and inconvenience, we pretty much settled on her not travel, another reason is the travel is non-essential.