Eleanor is incredible, for awhile in our four player fellowship we called her Queen Eleanor and voted her the most important hero in the group. Yes in solo she generally has a 33% chance to be helpful, but that number climbs up with each player added ensuring that by the fourth player you can pretty much guarantee at least one treachery being revealed.
Enemies we can deal with, locations clog up the staging area, but treacheries many times are game-ending and having Queen Eleanor to be able to swoop in and save us in our most dire need is incredible. Countless times she has saved us, sometimes multiple times in one scenerio.
Also as mentioned her with a Gondorian Shield is a nice backup defender if no treachery card is revealed. She also combos well with Blood of Numenor, Spare Hood and Cloak, Silver Lamp, Livery of the Tower, and Unexpected Courage if you want to use her in a defender/cancellation combined role.
For Solo she may not be the most efficient but when the fellowship assembles she is truly the star of the show.