Merchants can take apart cursed belts and amulets and use their non-cursed components to craft magic items, or else sell them to people who can.
Hence them being Shop Fodder. The Hero married both Gwaelin and the girl from the inn, and their respective children founded different kingdoms.
You can spend the night at the inn carrying Gwaelin and followed by the girl, and it won't change either of their behavior afterwards. Perhaps the ladies were already sweet on each other as well?