This page of our guide for Assassin's Creed Odyssey contains the list of all side missions found on Chios, one of the islands in Petrified Islands archipelago. Here you can find a dozen of side quests.
Clothes Make the Daughter
How to start: Speak with the future warrior.
Description: Collect parts of the warrior set. You can find them in the places marked in the picture above. Every item is guarded by enemies - you can either fight with them or sneak and steal the piece of equipment.
Collect all the parts and give them to the woman. This ends the quest. As a reward, you get a good level 49 sword.
How to start: Speak with the boys' mother.
Description: Go to the farm to rescue the woman's sons. Look at the first screen - the mission's starting point is marked with orange, green marks the place with the boys.
Boys are kept in provisional camps. The best way to rescue them is to approach their cages unnoticed and hit them. You don't have to escort the boys which means that you can run away from the enemies. Rescue both sons. Go back to the mother to end this quest.
Chip on Your Shoulder
How to start: Speak with the man.
Description: You have to go on Lesbos and kill the island's leader. The man can be found in the Leader House. Kill him to end this quest and receive your reward - armor.