Uzbekistan to Vancouver

Hi,
my mom had a tickets from Tashkent (Uzbekistan) to Vancouver (Canada) through the China (Tashkent ->Beijin ->Ganzhou->Vancouver (2-3 hours connection time between planes). The same airport, the same terminals.
Customs officer in Uzbekistan doesn't allow for her cross border, because she doesn't Chinese entry permit. Does she really need this visa, if she going transit through the China and she had tickets to the final destination (Vancouver)? She didn't plan to stay in China more than connection time (2-3 hours). She is also Canadian permanent resident (she had a Canadian PR card).
Does she need to apply for an entry permit (regular or transit)? This is rules was applied for summit time (BRICK summit) going in China right now....???