Unit Analysis by Team BethelFrankel
Class
Healer with very minor select-tile conversion and crowd control.
Overall
A
Advantages
+Conversion value even as healer (with flexible placement and guaranteed second turn too)
+Equipment can sometimes lucksack significant additional sustain value
Disadvantages
-Relatively weaker active healing output than the other healers (unless specific pathing is used with her lantern)
-Has diminished role in higher level accounts now that Roy exists
-Blind is extremely unreliable, 2 layers of RNG one to inflict, and one to proc.
Explanation
Nadine trades some pure active healing output in exchange for additional conversion. The nice part about this is that conversion itself can lead to healing output as well by allowing for Nadine to trigger a stronger chain combo, which means that Nadine can fix her own weakness with proper play. And given how valuable conversion is as an effect (especially freely placeable conversion), this is a fine trade-off, making Nadine very valuable, even when a healer isn't required.
With that said, the introduction of Roy poses an interesting question to players who have both -- although Nadine has some cheese that Roy doesn't and is generally more consistent and simple, Roy presents a much higher conversion and healing cap. The final call will be up to you, but it is more likely than not that Roy will do everything you want Nadine to do, except noticeably better.