1)
Why does the Torah refer to Miriam as "ha'Almah" (young maiden)?
1.
Rashi (citing the opinion of R. Elazar in Sotah 12b): Because she went 1 with the swiftness of a youth (an Elem).
2.
Sotah 12b (citing the opinion of R. Shmuel bar Nachmeni: Because she concealed her words. 2
1
Oznayim la'Torah: The Torah specifically says "va'Telech," and not 'va'Taratz,' because running might have given away the fact that she and Yocheved were related to the baby, and had an interest in his wellbeing.
2
Torah Temimah: She acted with discretion by not telling Bisyah that Yocheved was the baby's mother.
