There are several family trees to the Thidrekssaga.
Note that in the German legend, the Amelungs usually referred to the Thiðrek and his followers, who had followed the hero in exile. But in the Thiðrekssaga, the Amelungs were Thiðrek’s enemies, Erminrek, his uncle, and Erminrek’s followers.
Thidrek’s first wife was Gudilinda, daughter of King Drusian of Drekanflis.
Since Hildebrand (Hildibrand) is a prominent figure in the Thiðrekssaga and other Germanic legends, as a companion and mentor of Thiðrek, I have included a family of the Fenidi (Venice) under the Amelungs, which is tree below.
Attila was a historical figure, who was made popular in German and Norse legends. There is a variation of spelling to Attila’s name, such as Atli in the Norse legend, and Etzel in the German. In the Thiðrekssaga, he was called Attila. In the Icelandic legend, Brynhild was related to Attila (Atli), but in the Thiðrekssaga and the German legend there was no relationship between these two figures.
The famous Burgundian family was known variously as the Niflungs and Guikings in the Norse legend, and the Nibelungs among the Germans. In Thidrekssaga, they were called Niflungs.
Sigmund and his son Sigurd was called the Volsungs in the Icelandic Volsunga Saga. But in the Thidrekssaga, they were known as the Tarlungs.
According to the German and Norse legends (at least the Icelandic legend), Velent was known as Weland or Volund, but was more popularly known as Wayland the Smith, among the English-speaking countries. His son was called Witege in the German countries and Vidga in the Norse regions.