That said people often confuse druids who roleplay their alignment and neutrality well. They have alot of things that they dont care about and some things they care about to the degree that they would kill people for transgressing on it. I dont think 'druids have to be some form of neutral' is still in the game for PC's but generally thats how they were always portrayed.
Druids care about nature and their grove so they would be upset if someone upset that balance. They are also rational beings who can understand that the Tieflings have a concrete option to get out of their hair if they would actually bother to help them. If you "side with" the druids now Kagha encourages you to genocide the refugees because she is xenophobic and part of a hate group. That is bad writing.
If id have to voice a complaint it would be that to many of the druids inside the grove (where you find her threatening the child) have no issues with it whatsoever. THAT is abit off. Them respecting her rank is 1 thing but seeing no problem with it another.
This plays into that idea that the other druids are scared of the refugees destroying their livelihood (even though the Halfing trader is fine with them) and look to Kagha the demagogue for easy answers. I don't understand how they think Kagha is doing what is needed had you not conveniently showed up to do it for her, since she never undertakes anything against the Tieflings on her own initiative.