Here is a quick and simple guide on how to complete the side quest / Link, Old Duke and the Little Lady.
This quest first becomes available as soon as you unlock the Link Ability. It can however, easily be missed due to not actually being shown on the map until you are close to the actual quest and only then will it show.
For this quest you need to talk to the Duke who is worried about her little daughter whom owns a shop but for some reason has gone missing.
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