What to do if you hurt your mom by accident and you feel really bad?

My mom and I have a great relationship, we do everything together, but sometimes we argue over little things, and she is stressed out alot cuz she is s single mom and always has alot going on. This time it was over watering the plants, which she accused me of not doing, but I did do them, just poorly. Long story short we started arguing, nothing vicious just normal bickering, and i kicked one of the little tennis (which our dogs use) against the wall, which pissed her off. So she kinda came at me threatening to kick me, and i defended myself, and we had a small physical fight. I accidentally hurt her by pushing her away, since I'm a guy and stronger. I'm 15. Now she's mad, and I want her to know i was just defending myself and i didn't mean to hurt her