This may be a genealogical sketch for her. If so, this is a posthumous portrait. The portrait in the genealogical sketch is over 100 years out of date.
From Lady Petronilla's photostram on flickr. Also posted to the Early 1500s - 1470 to 1550 Album.
The bodice appears to have a three-banded under-bodice beneath a vest-like over bodice. The elbows are covered by slashed arm bands. The caul that lines her Steuchlein head cover is cut to also cover her forehead.
Keywords: 1525, Cranach - Louis the Elder, Elisabeth von Baden, German, jeweled Steuchlein headdress, caul, choker necklace, necklace, neck band, fitted under-bodice, pyramid neckline, vest over-bodice, epaulettes, long close sleeves, slashed arm bands, flared cuffs, waist band, natural waistline, over-skirt