I have her maxed out at lvl 80, 7*/ gear 10 currently. She is a very solid character and I use her in arena from time to time..
In that 5's/ Leia/ old Ben team the AI tends to focus on her first and she gets stunned a lot and is usually the first to die without contributing much. When RNG goes your way she can be very effective with counters, stuns and assists but I find her performance to be too inconsistent to depend on.
I still enjoy her regardless and would like to find a better setup where she can shine.. Maybe an assist/ counter/ stun team