Fantasy novel with 40 year old protagonist

Description:
I aim to write a fantasy book where the main character is not a teenager or just after her teenage years but a 40-year-old woman who brings a different perspective to the fantasy scene. With more life experience, she sees more, understands more, knows that her time is precious, and will only get involved after carefully weighing the pros and cons. She's seen things and done things and is unimpressed by childish drama. She respects herself and demands respect from others, but she will otherwise teach them a lesson in the most subtle way possible.
I find that fairies and dragons have been overused in the fantasy genre and would love to change this by lacing my story with new characters inspired by Romanian folklore - such as "iele" (beautiful maidens known to sing and dance crazy dances at night, who can poison wells, abduct or render mute people that see them), "Muma Padurii" (literal translation "The momma in the forest" - a witch/spirit of the forest that calls strangers to her by calling their name in different voices of their loved ones, only to lure them into her lair), as well as deities from the Dacian mythology.
The main character starts off by thinking that life cannot offer her any more surprises. Nevertheless, she will have to embark on a journey that will force her to interact with many of these characters and change her sense of reality.
Lastly, I would want the book to tell my readers that their lives don't end when they turn 30, 40, 60 or 80, no matter where life took them by that point. We all have a mark to leave and magic in us. The next adventure is just around the corner.

Logline:
At the age when one drank enough nectar and poison, when they've seen and done it all, every day is brought on by pure inertia, only to bring you closer to your imminent demise, and the last thing you expect is to embark on a fantastic journey filled with magic and creatures long forgotten.