Well I just figured that the bracelet was important because Morgause said it was given to her by her mother but it bears the symbol of Gorlois's house, something which Gaius suggested that only Morgana or Morgause would wear (i.e. because they are both Gorlois's daughters). It explains why the bracelet would mean something to both women (It was from their father's family) but not why Morgause's mother had it.