"Now when Rachel saw that she bore Jacob no children, Rachel envied her sister, and said to Jacob, 'Give me children, or else I die!' And Jacob's anger was aroused against Rachel, and he said, 'Am I in the place of God, who has withheld from you the fruit of the womb?' So she said, 'Here is my maid Bilhah; go in to her, and she will bear a child on my knees, that I also may have children by her.' Then she gave him Bilhah her maid as wife, and Jacob went in to her. And Bilhah conceived and bore Jacob a son. Then Rachel said, 'God has judged my case; and He has also heard my voice and given me a son.' Therefore she called his name Dan. And Rachel's maid Bilhah conceived again and bore Jacob a second son. Then Rachel said, 'With great wrestlings I have wrestled with my sister, and indeed I have prevailed.' So she called his name Naphtali. When Leah saw that she had stopped bearing, she took Zilpah her maid and gave her to Jacob as wife. And Leah's maid Zilpah bore Jacob a son. Then Leah said, 'A troop comes!' So she called his name Gad. And Leah's maid Zilpah bore Jacob a second son. Then Leah said, 'I am happy, for the daughters will call me blessed.' So she called his name Asher. Now Reuben went in the days of wheat harvest and found mandrakes in the field, and brought them to his mother Leah. Then Rachel said to Leah, 'Please give me some of your son's mandrakes.' But she said to her, 'Is it a small matter that you have taken away my husband? Would you take away my son's mandrakes also?' And Rachel said, 'Therefore he will lie with you tonight for your son's mandrakes.' When Jacob came out of the field in the evening, Leah went out to meet him and said, 'You must come in to me, for I have surely hired you with my son's mandrakes.' And he lay with her that night. And God listened to Leah, and she conceived and bore Jacob a fifth son. Leah said, 'God has given me my wages, because I have given my maid to my husband.' So she called his name Issachar. Then Leah conceived again and bore Jacob a sixth son. And Leah said, 'God has endowed me with a good endowment; now my husband will dwell with me, because I have borne him six sons.' So she called his name Zebulun. Afterward she bore a daughter, and called her name Dinah. Then God remembered Rachel, and God listened to her and opened her womb. And she conceived and bore a son, and said, 'God has taken away my reproach.' So she called his name Joseph, and said, 'The LORD shall add to me another son'" (Gen. 30:1-24).
Although we only get a glimpse of the family dynamic here during this seven year period, it is enough to illustrate the intense competition for Jacob's attention and love. Some men might think it would be great to have women fighting over them like this, but I'm not sure Jacob would agree. Both women were desperate--one to be loved and the other to bear children. Perhaps they both got what they desired eventually, though neither were fully satisfied it would seem. God was clearly involved, both granting and preventing conception as He saw fit (cf. 29:31; 30:22). Jacob realized this, and we would be wise to contemplate that fact even today (cf. 30:2; Psa. 127:3). The agitation between the sisters would be translated to their children, as will be shown in the coming chapters. Although Rachel was the favored wife, her behavior is not shown here in a positive light. Her envy over Leah's fertility, her irrational and exasperated plea to her husband, and her delight in overcoming her sister by giving her own maid to her husband sexually is not very impressive. Reuben was probably around 4 years old at the time he collected the mandrakes. The emphasis Rachel placed on the fruit is confusing here, until one learns that they were believed to promote fertility. Then her behavior makes perfect sense. Since God is not giving her what she wants, she turns to superstition out of desperation. This fails to bring her the result she yearned for so strongly.
Jacob may have had more daughters than one during this time frame, though we cannot know for certain. We do know that at some point he had at least one other daughter besides Dinah (cf. 37:35; 46:7). Dinah is likely only introduced by name among the births of the sons due to what would happen to her in Genesis 34. There is nothing in the text itself that demands the children were conceived and brought to term with no overlap; in fact, such is mathematically impossible (i.e., 12 non-twin babies x 9 months each = 108 months of pregnancy = 9 years). Thus, some of these women were pregnant simultaneously to squeeze twelve births into seven years.