ve'et-hanefesh asher-asu veCharan - and the souls that they had made in Charan
These words, in the plain meaning, refer to the slaves and maids they had acquired while in Charan. The word asu (made) appears as describing acquisitions in Devarim 8:17 "my strength and the might of my hand made me all this wealth."
Midrashic approach to the word asu is found in Bereishit Rabbah 39:14 where it is understood as applying to the converts Avraham and Sarah managed to make in Charan and whom they took with them to the land of Kenaan. Avraham converted the males, Sarah the females. This is why the Torah speaks of that phenomenon in the plural, i.e. "they had made" each one separately. We also find that Yaakov did the same as his grandfather Avraham as the Torah speaks of his sojourn in the land of Kenaan in these words, "and Yaakov settled in the land in which his [grand]father had succeeded in making converts" (Bereishit Rabbah 84:4). From this we learn that Yaakov was also making converts.