To be fair, did you see her MP bar the past few chapters?
Its like all those phone screenshots at 15% battery life except so much worse. I would think that if your life depended on a MP bar never depleting and you can freely check it, MOST PEOPLE WOULDNT LET IT DROP BELOW HALF!
It doesn't matter that it only depletes 1 MP a minute and you have nearly 100 MP left. Why are you letting the bar get that low?