Talk to Blandine, she will mention she is waiting for her husband, a sailor.
Talk to Grimr in the docking area who will say he's bored. Then talk to Zexu who's standing on the crate next to Grimr and he will mention Blandine being at the docks again.
Exit the docking area and talk to Blandine again. You'll receive a cut scene involving Blandine and her daughter Celestina who runs off.
Go up to the Gold Smithing guild and talk to Celestina to accept the quest, she will ask you to obtain a Sand Charm.