I didn't really get the sense of inheritance (herança) from your dictionary link. Wouldn't "share" be the best translation in English? Of course, in this context it most likely means a share of an inheritance so it's just a minor quibble.
there is no clue how to guess if the jewelry was the only inheritance that was left or if there were more things to share... =/ but probably all the jewelry was supposed to be delivered to that family...
This doesn't make sense as a measure word though. Or does it..? Anyway to further my understanding, could one also call it "the family's wealth" or "heirlooms"?