Also Spanish (Modern). There are 1.670 bearers of this name in Spain and the average age of the bearers is 14 (source: Instituto Nacional de Estadística).https://es.m.wikipedia.org/wiki/Lea (Leah in the Spanish Bible)
In 2018, 40 is the most common age for an American (U.S.) Lea who is registered female with the Social Security Administration. It is the 1223rd most common female first name for living U.S. citizens.