My daughter would need to apply a chinese visa while her school trip in Thailand

She has now a X2 when living here in China. It shall expire just when she is in her school trip in Thailand. Local authorities here says they are not able to extend that X2 so she should apply a tourist L there in Thailand during the school trip. She flies to Bangkok and continues to Koh Samui. Is it possible to apply in Koh Samui or how long it would take time in Bangkok? Could we somehow ensure and preparthe application process beforehand to make sure everything goes smoothly and fast?