I think the weird part of this is that it was put back where it was left in the first place. That makes it seem like she was trying to "teach you a lesson" I agree it is incredibly childish, and says a lot about her character (as does the comments she made to OTHER people instead of speaking to you directly).
If it's worth making an issue over it is for you to decide.
If it was me i'd just figure she was an immature bitch and try to get over it. If I couldn't after a few days i'd politely speak to her about it (it would probably take a few days to get to the point where I could be polite about it anyway. Stupid, petty crap like that really annoys me since I wouldn't do that to someone else).

~What is leads to what will be, and all will be well, if we do what is right.~