Her sword or her staff, honestly. She's had the sword since she started as Tempest and has somehow yet to lose it (even after she died), so there's just sentimental value there. The staff is one of the few things she spent money on, and all it really does is channel and hold magic. So like, she can cast a light spell and the gem at the top will hold it there without her having to use the energy to do it. And it works a channeling point for her more difficult spells.

tl;dr the things she can kill with. She had very, very few things she kept with her otheriwse

What does Ed think of Clover's magic? In general, overall, w/e