Because it's about the Elves, it's safe to add Sebille to the mix, it relates anyway as Saheila is also part of her next quest.
So in Lohse's run, I managed to talk Sebille into killing the Mother Tree, don't know how exactly, but I did it, after killing the Master and delivering his black heart. I'll return to the Master yet, but first things first. In Scarlett's run I did almost everything the same way, killed the Shadow Prince, delivered the heart and when Sebille talked to Saheila, she automatically refused to kill the Mother's heart, telling Saheila, that she's now rooted. Perhaps some steps might have been done in a different order, I guess (but not sure)? It's not a big deal, just a strange thing.
Now to the Master. In Lohse's run, Sebille first called me darling, then taught me her song and we killed the Master. In Scarlett's run, she taught me the song without ever calling me darling, we killed the Master and after that deed was done, she started to call me darling. Does she have a greater affection towards Lohse (I wouldn't blame her, if she does indeed)? XD