1. She's a Shadow Druid. She even has Faldorn's writings, a Shadow Druid from BG1, in her chest in the library. Shadow Druids are very much "screw literally all people" militant druids that legitimately will murder entire villages just to preserve what they see as the balance. Slaughtering innocent refugees in order to be able to focus on nature is LITERALLY Faldorn's Shadow Druid sect territory. It's her bread and butter.
2. "Druids can create goodberries with a lvl1 spell so the food situation makes no sense" is poorly thought out criticism. How many spell slots must they expend every day? Why? Spell slots are a resource the druid need to do things like communicate with animals and carry out their duties. Kahga knows this.
1 goodberry spell feeds 10 people for a day. A lvl 1 druid has 2 of these and im going to assume that most of the druids will be higher level. The idea that they cant spare 5 or 6 (guessing on their numbers, could be less) lvl 1 spells for goodverry and 1 for water is laughable. Noone would take that as a serious reason why feeding these people would be a problem.
They wouldnt need to help them beyond that though. Keeping them fed also preserves the balance as it is. In the sense that a status quo doesent change anyway.
That said their options to help the Thieflings are somewhat limited without getting involved in some way which might make them a target for the Goblins. So to take the druids their perspective, what should they do?