My wife was adopted from South korea when she was about two years old. She was born in 1980 and would have come to the US in about 1982. I question whether she is a US citizen. Her sister who was adopted at the same time just went and took her citizenship test, at the completion they told her she was already a citizen. Also the immigration office will not give her a refund for the test, which I find absolutely absurd. Is their a database or something I can use to confirm my wife's citizenship status? Thanks for your time.

Babies that are adopted by American citizens become US citizens.

Yes, if and when she was adopted, that makes her a citizen, she should have been issued a birth certificate at adoption that makes it appeaar she was actually born to the US couple