Shockingly she is still a good leader and several thousands years old so yes younger, but by not fucking means young in the 2nd age. She didn't start that way out of the womb, but she is still ONE OF THE OLDEST ELVES/BEINGS ALIVE AT THIS POINT. She acts more like a petulant child than just about anyone else.
Cool not all leaders are 1. Good Warriors 2. Good generals/leaders in war. She was never stated directly participating in any fights/wars. SHE MIGHT HAVE fought, but there is no facts that she did.
I would be completely fine with her being a mentor/council for the leaders, she has always been known as being one of the wisest/most knowledgeable beings including Maiar. IF YOU HAVE to force into fights, make it happen rarely (like 1-2 times) and make it more a metaphysical/semi-magical fight with Sauron, that would be appropriate and still show case her power.
It makes it unbelievable when you have a being recognized for her wisdom/knowledge acting like a complete moron throughout the first two episodes.