She doesn't really fullfill the same role as a mage. Once you SAW her she'll attack and heal simultaneously for 90 sec so she can have more than one useage. She will deal less damage than Garania but she will attack a bit faster and heal at the same time. Her range is longer but her splash is smaller.

All in all, different roles. As a healer/mage combo she is quite nice, as a pure damage dealer a mage will be better. With some correct timing you could place her down and skip having another healer for some encounters while still having someone that deals damage, but if constant healing for more than 90 sec is needed she will obviously not be the best choice.

Just go and get her damn it, she looks great artwise and it's a black.

(note, i compared DMM stats and i dunno if bishops ever got an atk boost like mages did, so it could be that she deals more standard dps than Garania does atm)