Complex sentence: She then joined Australian female trio Eden AKA who signed to Columbia Records in the U.S. Their 1999 self-titled album included Stephen Stills and Scarlet Rivera, and they performed in Canada and the U.S.A. at the Lilith Fair in 1998 and 1999.
Split into simpler sentences: She then joined Australian female trio Eden AKA, who signed to Columbia Records in the Unnited States. They released a self-titled album, and they performed in Canada and the United States at the Lilith Fair in 1998 and 1999.