I'd like to point out also that characters in the Narutoverse tend to be very young - Shira is older than some of the Jounin were at this point (though she is not as skilled and I am not intending to imply or state that) so she has had more time to condition herself to the weight of the blade. While she's become very accustomed to bearing the weight of the sword, she's almost completely foreign to actually swinging it in such a fashion that it could be considered a weapon. I intend fully for her to struggle learning to use it as a weapon rather than a symbol of heritage.
So while I intend to show exhaustion as she uses the blade as a weapon, she will not be fatigued from carrying it around. That is a burden she got used to a very long time ago. I assume that's okay, Prince? If not, I guess I'll have to change stuff around.