Okay, being able to conjure something from nothing, meaning breaking conservation of matter is automatically a huge deal. Which is often why most common conjuring power are just energy blasts with no forms or practical use aside from basically rapid oxidation of matters it touches.
But it's often overshadow by the fact that everyone in the story can conjure something so maybe conjuring water (!) is not a big deal.
And I could also rationalize it by saying since conjuring likely costs the user's energy which need to be replenished by consuming food, it's no different than eating food and in turn use that energy to throw a rock at someone. So instead of energy to energy, it's now energy to matters. Which is still a big deal.
Which brings me to her power, if she can control the shape and pressure of the water at the conjure point (meaning she does not require the presence of water nearby), she could ostensibly fire a tiny (or large) stream of high pressure water jet that doesn't take much to easily pierce flesh and is near invisible and leave no trace (the droplets evaporates or dissipates post-exit wound) that only a super detective who is specifically looking for it may later discover the wet marks.
And if she choose to not fire a single burst, but a continuous stream then she can literally slices a person in half with it.
This power makes her an unassumingly deadly if you don't stop to think about it.