Num 26:58-59
These are the clans of Levi: The clan of the Libnites, the clan of the Hebronites, the clan of the Mahlites, the clan of the Mushites, the clan of the Korahites.—Kohath begot Amram. The name of Amram’s wife was Jochebed daughter of Levi, who was born to Levi in Egypt; she bore to Amram Aaron and Moses and their sister Miriam. To Aaron were born Nadab and Abihu.
1 Chr 6:3
The children of Amram: Aaron, Moses and Miriam. The sons of Aaron: Nadab, Abihu, Eleazar and Ithamar.
Midrash
Unlike most women in the Bible, Miriam is never called a wife or mother and no descendants are mentioned. But various Rabbinic texts attempt to fill in the gap.
One tradition identifies Miriam with Ephrath, the second wife of Caleb [II Chr 2:19], thus making her the mother of Hur, the grandmother of Uri, and the great-grandmother of Bezalel, the chief artisan of the Tabernacle [Targum Chr; Sifre Num 78; Sotah 1b-12a; Shemot Rabbah 1:17; among others]. Midrash further explains that King David was the descendant of Miriam and Caleb [Sifre Shemot 72-73].
Josephus, the late first century Jewish historian, states a tradition in which Hur [Exod 17:10-12] is married to Miriam [Antiquities 3:53-54] in which Bezalel is the grandson of Miriam [Antiquities 3:105].
In addition, fragments in the Quamran (Dead Sea) Scrolls have been interpreted by some scholars to imply that Miriam is the wife of Uzziel, her uncle, the younger brother of her father Amram, and is the mother of Sitri.