The most recent quake, initially gauged at magnitude 6.3, hit a sparsely populated area of the Xinjiang region near the Kazakhstan border on Wednesday morning.
The updated casualties figures were published by authorities of Ngawa Tibetan and Qiang Autonomous Prefecture of Sichuan on its official Weibo social network page.
The quake injured at least 263 people with several still missing. Maxence Vallon, 18, was wounded in both legs; while the Canadian woman, who declined to be named, suffered slight injury in the head, the report said.
The brothers were staying in a hotel with their mother in Jiuzhaigou when the quake struck. His brother Romain, a student in Beijing, said they were seeking shelter "when a big stone fell and hit my brother right in the leg".
Of the 19 people reported killed, eight were thought to be tourists, two local residents and nine were not yet identified, Reuters reported.
According to the US Geological Survey, the natural disaster was 9 kilometers (5.5 miles) deep. Shallow earthquakes tend to cause more damage than deeper ones.
As of late Wednesday morning, the death toll from the magnitude 6.5 quake that jolted the famous Jiuzhaigou National Park had risen to 13, with more than 175 people injured. The U.S. Geological Survey measured the magnitude at 6.5.
The Sichuan government said that as many as 31,500 tourists had been evacuated from the quake zone, leading to traffic jams on the narrow roads. The Civil Aviation Administration of China (CAAC) has instructed airports to keep track of available runways and gate positions while asking airlines to help with emergency evacuation of tourists in the disaster-hit area. It was the strongest quake in The Jiuzhaigou National Park since 2008.
More than 30,000 people have been evacuated from the Unesco World Heritage Site, famed for its lakes and waterfalls.