I thought when Hacchi (wow, I couldn't remember his name, had to look it up) healed it, she said something about how he was completely destroyed and she couldn't even find a piece of him. And then he explained that her power is like his and that she shouldn't have needed to find a piece. So I think it was more a her not understanding her power than being limited kinda thing.
Edit, found it:
Here's when she says it:
http://www.onemanga.com/Bleach/227/13/
And here's when Hacchi does it
http://www.onemanga.com/Bleach/228/13/
XI Wiki



