I like her a lot actually. She's in my main team (currently top 10 but usually top 50)
Her group heal doesn't proc very often and I think it may be glitched because a crit doesn't seem to give the heal all of the time.
Her evasion usually stays up and I don't see her getting low in health often unless the AI really focuses her. Even then there is time to heal her up.
Her damage, while not best in game, is quite good if you gear and level her skills. She's almost 5* for me and maxed gear for her level (49, gear 6).
For reference in arena I am running Sid (lead), JC, Lumi, Dooku and Ahsoka. Currently rank 5 but I'm sure I'll drop back again before reset.