Frozza was born in Venice as a daughter of Doge Otto Orseolo and his wife, Princess Grimelda of Hungary.

[1] Her father, grandfather, and great-grandfather were all Doges of Venice, and were members of the House of Orseolo, whose ancestors were the first historical Doges of Venice, the Ipatos.

[2] Her brother was Peter the Venetian, King of Hungary[3] and she was possibly a sister-in-law of Judith of Schweinfurt.

She married Adalbert, Margrave of Austria, of the House of Babenberg, and later took the name of Adelheid.

They had 2 sons: Leopold & Ernest, Margrave of Austria.