A couple things caught my eye in the banshee’s description from the Monster Manual:

“The vanity that inspired the banshee’s cursed creation persists in undeath.”

And:

“A single glimpse of itself is enough to send a banshee into a rage.”

Each may explain why Agatha wouldn’t appear for Sister Garaele when she came calling in Conyberry.

Acutely aware of how undeath has ravaged her beauty, Agatha hides herself away from those she is forced to inhabit the material world with, because the exquisite beauty that defined her in life has been replaced with a horrifying visage in death. Agatha’s vanity makes it such that, if she cannot be beautiful, she would rather not be seen at all.

Then one day a young elvish woman tiptoes into her grove, wanting a word. Garaele is young, beautiful, and full of life. A reflection of what once was, but will never be again for Agatha. And so Agatha remained hidden, embittered by Garaele’s presence.

According to The Ghost of Conyberry, Agatha is not the banshee’s proper name. Rather, it is a corruption of the elvish surname Auglathla, which means “Winter Breeze” in an older elvish dialect. This is knowledge that can be used to flavor your encounter, because her proper name is all that remains of Agatha’s beauty in life. It is the one thing about her that could not be corrupted by the banshee’s curse. Hearing her proper name spoken aloud would move her.

With that in mind, perhaps Agatha will only appear for intruders who address her by her seldom-used proper name. For characters who address the banshee as Auglathla, consider granting advantage on the Charisma (Persuasion) check necessary to enlist her help.

+++

If you’d like to support my work, please consider checking out my supplements for Lost Mine of Phandelver and Dragon of Icespire Peak over on Dungeon Master’s Guild! All of my titles are Free/PWYW offerings.