Elisabeth Sophia was born on 13 July 1589, either in Berlin or in the adjacent city of Cölln, both of which were then located in the Margraviate of Brandenburg.

On 27 March 1613, Elisabeth Sophia was married in Berlin to Janusz Radziwiłł, a Polish noble who had been widowed the previous year by his wife, Zofia Olelkowicz Słucka.

Janusz died on 3 December 1620, leaving Elisabeth Sophia a widowed mother at the age of 31.

[5][6] On 27 February 1628, Elisabeth Sophia entered into another marriage, this time with Julius Henry, Duke of Saxe-Lauenburg.

On 25 February 1629, Elisabeth Sophia gave birth to another son, Francis Erdmann, Julius Henry's heir to the Duchy of Saxe-Lauenburg.