I think I know why Reaelle was able to heal Kalidia now why she and Abigail are still alive. The Cameriellia are using the songs against the witches they twist them into hatefulness. They did the same with the sickness infusing something man made with witch magic. Which exactly what Reaelle is a witch born to civilian human father. What if witch aren't vaccinated against anything they use healing seeds to cure sickness they wouldn't have the immune response to fight with. But Rea having a human father and being poor would have her vaccinated maybe without her knowing or they could fought about it. Still when took the sickness the first time she didn't have her normal reaction because then human side of knew what to do.
Now when Abigail linked with her with it increased her power when fold like Adler with her biddies she drew Abigals power to increase her own power ten fold to stop death.
Bonus-Alder needs to give Tally back they get back to Fort Salem find a new biddie and give Tally back to us. Rea and Abigal are going to need her more than ever
