Are there any Christian or Talmudic sources that clarify whether Tamar was considered an Israelite or a Canaanite?

In St. Matthew's genealogical account of Jesus' ancestry, only four women are mentioned. Interestingly enough three out of the four are clearly non-Israelites: - Rahab was a Canaanite by birth. - Ruth was a Moabite by birth. - Bath-sheba was a Hittite by marriage. That being said, the status of the first woman mentioned (Tamar) seems unclear. We read in Genesis that > "Judah saw ... [a] Canaanite whose name was Shua, and he took her, and > went in unto her. And she conceived, and bore a son, and he called his > name Er." It is my understanding that from a Jewish perspective (based on an interpretation of Deuteronomy ch. 7, v. 3 -4), this would make Er and all the other sons of Judah by Shua, Canaanites, and not Israelites. Later, we read that Er would marry a woman named Tamar of whom we know nothing about: > "And Judah took a wife for Er his firstborn, and her name was Tamar." From what I have gathered, this would make Tamar a Canaanite by marriage. Please correct me here if I have made a mistake.