The party had probably grown considerably in the 8 years since leaving Jerusalem. Ishmael died along the way but Ishmael had two married sons and five daughters that married Lehi's sons and Zoram. All seven of these young families would have been in prime child bearing age. Even Sariah and Lehi had two more sons, Jacob and Joseph, on the way. Interestingly, Nephi doesn't talk about his own children. He may not have had any sons. This statement is based on the fact that when he handed down the plates he gave them to his brother Jacob. Also, when he was near death he appointed "a man" to be king. There is no discussion of any of Nephi's sons even being considered for the position. See Jacob 1:1-3,9.