User blog comment:FairyRaven/Fairy Tail Chapter 437: Magnolia, Review and Commentary/@comment-7418318-20150525093151/@comment-9595671-20150525224008

While poison magic does seem like an obvious choice, you have to remember Cobra's with CS now. So learning it to support Cobra doesn't help unless he ended up showing up pretty often.

She was holding a staff though, so I assume that she's atleast learned a form of Holder Magic.