No, she is pretty impressively dumb. Staying within range of two enemies and not moving a single inch away before attacking any one of them with that range is very, very stupid. Auguste is even worse on paper, just staying still all the time, not even bothering to run. In practice, that might actually be a good idea when all enemies just want Reinhilde dead, but.
EDIT: And I believe using the Plume more than once per game will lead to C route (don't think the FAQs said otherwise, and I don't want to test it out, honestly). I don't want to diverge routes this time around (planned to go B the whole way), so I'll have to pass on that skill. The game sorta doesn't warrant that level of overkill durability anyway, although um wow, infinite auto-revival for three turns for your whole party is sorta broken as shit.