Her connections to mainland China are well documented. From Wikipedia:
“Pak was an overseas executive director of the China Overseas Exchange Association (COEA), an organization overseen by the Overseas Chinese Affairs Office (OCAO) of the State Council of the People's Republic of China.”
“At various times she spoke out in favor of the Chinese government's views, e.g. in 2012 calling all "overseas Chinese" to "defend the homeland” in the conflict about the Diaoyu Islands, and in 2008 opposing a resolution of the SF Board of Supervisors that criticized China for the Tiananmen Square massacre and other repression measures, passed on occasion of the Beijing Summer Olympics torch relay reaching San Francisco.”
“As revealed in a 2018 Politico report after Pak's death, among U.S. intelligence officials "there were widespread concerns that Pak had been co-opted by Chinese intelligence". These also extended to her work in organizing many "junket" trips to China for leading Bay Area politicians.”
Regardless of that, or the source of her kidneys, Pak is a textbook case of political cronyism, and how one person who never held elected office can use financial connections, backroom dealmaking, and sheer force of will to shape elections and policy for decades and steer the direction of a major city.