>>116188042A) She hasn't given any example of traveling back in time.
B) No it's not, not necessarily. There's plenty of ways to affect the past in the gunnerkrigg universe that could not be considered time travel. For instance, the creation of things like Jones before her creators existed. No one traveled back in time. Another example would be a god as described in this post
>>116186805 that exists unbound by time. You would not be able to call it time travel in that case either.
We have yet to see even a hint of anything that could be defined as time travel in this comic.