@voldtzeig I always go back and forth on whether to use water for hydration but I often come back to the conclusion that hydration levels are very important whenever IM dealing with stubborn issues. This would not be an issue if you eat like Peat (usually up to a gallon of fluids from fruit and milk), however many people dont do that.
Of course water is not the only thing to account for (salt is so important), but you can see how many fluids shes having and if that helps (if shes already getting an average amount of carbs/fat/protein. Not that more food wouldn't help, but moreso that it wouldn't be the main cause likely).
I can also add some experiences of having poor appetite all day and then drinking a few cups of water and regaining an appetite for a full meal.
Of course the opposite can be true if someone is over consuming beverages, but if youre talking about the instance of post partum + breast feeding I think this might be part of the issue (more water + minerals).