Who are the women in the tent?
Rashi, from Nazir 23b: Sarah ("Hinei va'Ohel"), Rivka ("va'Yvi'eha Yitzchak ha'Ohelah") Rachel and Leah (va'Yetzei me'Ohel...") (Bereishis 18:9, 24:67, 31:33).
Radak, Malbim: They are other women who sit in a tent.
What is the meaning of "mi 'Nashim ba'Ohel?
Sanhedrin 105b: Her blessing is me'Ein (a semblance of) that of the women in the tent (the Imahos).
Radak: She is blessed more than other women who sit in a tent.
Malbim: Women who sit in a tent will bless her.
Why is she blessed mi'Nashim in the tent?
Rashi (from Bereishis Rabah 48:15): Women in the tent had children and raised them; if not for Ya'el, this Rasha would have destroyed them. 1
Rashi: Also Ya'el lived in a tent, therefore the verse mentions Ohel in her Brachah.
Radak: She was zealous to 'help Hashem' from where she was, in the tent.
Malbim: She was in a tent and did valiantly. Bnei Maroz were cursed for remaining in their houses.
[Even though his army was wiped out,] had he lived, he would have gathered more men, for he was very strong and had many men (Etz Yosef).