Source in Chinese: The girl suffered severe traumatic brain injury along with a fractured femur & legs, and has been pronounced brain dead. The prognosis is very poor, the most optimistic estimate for her is a vegetative state, without respiratory support, that is no autonomous breathing, so she can only survive with breathing machines attached. The impact from the first car had slammed her head to the ground so hard she received cranial fractures and crushed brain stems which has damaged the respiratory and circulatory areas of the brain.
As to where the mother was, apparently she was going to the toilet inside a store. She had not known that Yue Yue had left the store (Possibly to wander around and play). The mother looked for her in a few stalls before hearing the garbage woman's cries.
Update 2 As pointed out by Stormflux : The girl has died from her brain injuries, both drivers have been detained. The first driver knew he hit her but he was afraid of getting in trouble if he stopped.
#11 jag2kn 
