She's not bad in a vacuum, she's only bad compared to other black healers (which we don't currently have) and her skill doesn't increase healing, so she costs more to deploy than Camilla and Chydis, but only heals more outside of skill. Most would consider her bad considering there are plats that are arguably better, but that's to be expected as she was originally an event unit. Why on earth she was made premium in our version is beyond me.