According to German historians, Świętosława was 15 years' old at the time of their marriage, while according to Oswald Balzer, she was aged 19 to 22.
Menurut para sejarawan Jerman, Świętosława berusia 15 tahun pada saat mereka menikah, dan menurut Oswald Balzer, ia berusia 19 sampai 22 tahun.