
Why do you think that?
Gunhild|Swjatoslawa|Sygryda, (Piast).
Father Mieszko I Dagon, Grand Duke of Poland
Mother Dubrava - Dobrawa - Dubrawka of Bohemia
https://finnholbek.dk/getperson.php?personID=I9403&tree=2
Herman Lindqvist (Swedish journalist and historian) puts forward the theory that the name Sigrid was a popular Swedishization of Świętosława and that Gunhild was the official queen's name. It's credible.