Well, your mom obviously over-reacted. Heck, its your iPod, I would be pretty angry too. Maybe when she gets back from work, you can calmly explain to her that you were not blaming her. (Being calm is actually really important - it helps to use "I" statements, which are "I was really upset when I saw the broken iPod" and so it helps the other person better understand your point of view.)
Best of luck, hope I helped !!