In rabbinic literature, the twin brothers represent archetypes of two major civilizations: Jacob is Israel and Esau is Edom (Rome). Thus, the narrative becomes a fight between the forces of good and the forces of evil.
We see glimpses of Rebecca's inner dialogue at the beginning and end of this week's Torah portion. In the opening verses of Parashah Tol'dot, Rebecca becomes pregnant with twins.
Abraham is promised that through him we will become a great and prosperous nation, as vast as the stars that light up the heavens in the dark of night and as numerous as the sands as far as the eye could see. But the covenant could only continue through marriage and offspring. So, as we read last week in Hayyei Sarah, Abraham sends his servant to search for a wife for Isaac among the tribe.