[quote=@Drifting Pollen]
<Snipped quote by ImportantNobody>

Technically true! However, a hundred-foot-long spear would be absolutely useless as a weapon. The thing would have to either be too heavy to move, or have a shaft so thin it would snap like a twig.

If you want to hit someone a hundred feet away with a spear, you use a [i]javelin[/i].
[/quote]

I thought of a funny application for the technicallity of the power. If she created a long enough spear she could stab the moon and crawl up it if she was wearing a spacesuit...and if the spear with thick and strong enough to support it. I don't think that's troll science, it would just have to stick in good, I think. But perhaps it would get torn out no matter what from the forces of its orbit, like if the moon material isn't tough enough.

Or she could create a weapon large enough to create its own gravity on par with a planet or even a black hole, but I'm just taking things to extremes here. 

Now she could create weapons too large to wield effectively but use other creative applications for them, but this power you have is perfectly fine and balanced to me if she uses it in the intended purpose.