Ælfgifu Wessex is widely discussed as the possible wife of Boleslav II of Bohemia. Charles Cawley comes to the conclusion that such a marriage is chronologically highly unlikely. There is no other source but the mention that she married "a certain duke near the Alps." Theories include that she may be "ADIVA" for whom a few coins have been found but newer research questions even the reading of "ADIVA" for these coins. Other sources suggest Boleslav may have had other wives besides Emma but do not name them. In other words, there is no source putting her in Bohemia.
Based on the evidence available I would propose to delete the marriage and discuss these possibilities in the respective bios only.