I... think I may have said that Sarah can recover from non-fatal injuries in her CS? Assuming she has the 'resources' for it, of course, which most of the time won't be the case. Think of it as an Elementa growing/recovering when allowed to absorb the thing it's made of. In fact, that's pretty much exactly what's happening.
Oh, and for the record; When the detached body parts will eventually melt, they'll completely dissolve into water. The same will happen with other injuries; Sarah effectively bleeds water instead of, well, blood.