In 2018, 20 is the most common age for an American (U.S.) Agnieszka who is registered female with the Social Security Administration. It is the 23, 047th most common female first name for living U.S. citizens.
― Anonymous User 10/22/2018
3
This is very common name in Poland, pet form is Aga.
Source: https://forebears.io/forenames/agnieszka