[@Vocab]
1) Having her magic basically buff her own fighting skills would be fitting as far as her straight-forward nature goes, but there wouldn't be any real applications of the power.
2) This was one of my earlier suggestions, but Cleopatra has clearly stated that no body-changing magic was going to be accepted.
3) There's already a character with clones, so this would be too similar.
4) This could work; she could use her magic to destroy anything she would hit with her hammer and rebuild to another form by also hitting it. But I'm pretty sure it's too broken of an ability to be used, similar to Homura's timestop.

[@The book of bad juju]
Barrier magic would actually be fitting in that context, and it could also be applied in a diverse manner. How would it sound if Julia used spherical barriers to both defend and to launch as magical projectiles with her hammer like a golf club, [@Cleopatra]?