Elder Miriam ran out of supplies and she needs three Lesser Health Poultices for the sick and injured refugees.
You can start this quest only if one of your team members knows something about Herbalism. You can find Elder Miriam on the far side of the camp behind the caged criminal. To make the poultices you need three Elfroots and three Flasks. You can find the Elfroot to the north of the village and you can buy the Flasks from Barlin. Make three Lesser Health Poultices then return to Elder Miriam.
You do not need to make the poultices to finish this quest, you can give Miriam three poultices from your own reserves. You need, however, to have a character with Herbalism in your party to start the quest. Morrigan starts the game with ranks in Herbalism so if you don't have any ranks in it, it is best to simply put her in your party to activate the quest, then gather the health poultices however you like.