I'm certain that Dona Isabel must have received several jewelry gifts as wedding presents, from her husband, family, portuguese nobility, closest royals... However, as private gifts, not much is known (nor confirmed) about it. I've always wondered about what gifts came from the Cadaval, the Palmela...not sure we will ever find out.
At the time of the wedding the press reported mainly on the gift from the late King Hassan of Morocco. He had a close friendship with the Duke, it seems. He presented the new Duchess of Braganza with a gold and diamond round necklace with a flower as center motif. The press reported only the necklace, but apparently the set could also comprised a pair of flower shaped earrings, as they match the necklace perfectly and Dona Isabel usually wears them together. (HQ posted by Tamara sometime ago)
This set is a favourite of the Duchess, who wears it often.