Here is the ancestor I am interested in:
https://www.familysearch.org/tree/person/details/G6MD-33Z She married her husband, in the US, in August 1909. Her birthday was listed at Dec 1887 on the rural Pennsylvania county marriage record. Other records say anything from 1883 to 1890. Her husband was born Oct 1889 (and I've found his birth record from his hometown).
I can't find any records of an Anna born to those parents for 1883-1890, but I did find one for Feb 1882.
At this point, I have two theories:
1. The Anna born Feb 1882 died young and they had another Anna that I cannot find the record for. I must admit I am pretty bad at looking through Slovak records
2. Anna lied about her age before marrying her husband, who would have been 7 years younger and her birthdate was actually in Feb 1882