Taking on her partial American lineage as an issue is racism. Racisim in its core is about taking genetic heritage as a worthy factor into anything.
I think you know nothing about China's thousands years history where we have plenty of "foreign" blood contributing to what Chinese is today. Name a few, Tang dynasty imperial familty started as half "foreign" Xianbei/proto-mongolic. 唐太宗/Taizong's priminister 长孙无忌/Zhangsun Wuji was Xianbei descent. The famous general 高仙之/Gao Xianzhi who faught Arabic caliphate in central Asia and latter to supress rebellions was from 高句丽/Goguryeo. While the rebel 安禄山/An Lushan was a Sogodian. Generals fought on the side of the emperor 哥舒翰/Geshu Han was a Turk, 李光弼/Li Guangbi was Khitan.
Bloodline was NEVER really something Chinese cared in most of our histroy except some people influnced by the west recently. If Chinese cared about it Chinese would not have existed.
Chinese was always a cultural concept, not a racial one.
诸侯用夷礼则夷之,进于中国则中国之。