This has been one of my staple favorites since the core set days, and one I still use often. It might be one of the most underrated and under utilized cards in the game. She basically makes it extremely easy to splash other spheres into mono lore decks while scratching the willpower itch at the same time. I will typically include 3x in any mono-lore deck I make, and then 1x of either one or two other song cards for whatever sphere or spheres best compliments whatever particular build I'm working on.
As the cardpool has progressed, her cost/stat ratio has been overshadowed by many of the more recent allies, and she is no longer the lone go-to source of willpower in Lore, but the minstrel/song combo is still a legit way to easily splash lore decks and is still great for resource smoothing even in dual sphere decks (although a bit pricey for tri sphere).
Definitely a great utilitarian card