根据Wikipedia:

1、她没有正面回答过关于她国籍的疑问--"Chinese nationality law does not allow dual citizenship and she did not answer a reporter's question regarding her status as a U.S. citizen at the time(June 2019)."

2、奥运宪章规则是允许双国籍、多国籍参赛--""Her goal was to compete for China in the upcoming 2022 Winter Olympics which the Olympic Charter Rule 41 by-law allows for dual citizenship or multiple citizenship."

3、她自己在微博上提到她收到了U.S. Presidential Scholars Program提名，这个奖是只针对美国公民和绿卡持有者的。-- "On March 1, 2021, she wrote on Sina Weibo that she was recognized as a candidate for the U.S. Presidential Scholars Program from San Francisco University High School in January. The scholarship is only open to U.S. citizens or legal permanent residents by the application deadline. She did not ultimately win the scholarship."

以上内容出自英文Wikipedia，在中文版的Wiki上并没有。但是中文Wiki在关于她国籍那里有如下注释: "中国不承认双重国籍。然而，根据中国法律，未满18岁儿童可与其监护人共同签字声明不保留外国国籍并决定加入中国国籍，但美国理論上不允许未成年美国公民放弃美国国籍。因此谷爱凌严格来说只有一个国籍，在18岁以前由中美两国各自表述。"

综上所述，关于她的国籍之谜应该有答案了。