[usurper]

I suspect this was deliberate so she could have dual citizenship.

It does not work that way, in order to become a citizen of another country you must renounce your US citizenship.

[jjotto]

Not true.

https://travel.state.gov/content/travel/en/legal/travel-legal-considerations/Advice-about-Possible-Loss-of-US-Nationality-Dual-Nationality/Dual-Nationality.html

… U.S. law does not mention dual nationality or require a person to choose one nationality or another. A U.S. citizen may naturalize in a foreign state without any risk to his or her U.S. citizenship…