Sibylle and her sisters were raised in the Frauenzimmer,[2] the chambers where the duchess Maria and her entourage consisting of female relatives and attendants lived a sort of semi-cloistered existence.

No male over the age of twelve was admitted, and at night the women were locked in, the key held by a trusted court official.

[2] In September 1526, Sibylle was betrothed to Electoral Prince John Frederick of Saxony in the Schloss Burg an der Wupper.

After lengthy negotiations about the dowry, the lavish wedding ceremony, preceded by an elaborate procession, took place in Torgau on 9 February 1527.

The correspondence between Sibylle and her husband during his captivity as a consequence of the Schmalkaldic War, showed a devoted and intimate couple.