Am I being a jerk or is my coworker?

I’m pretty sure I was a jerk. But I felt like the other person was being pretty *****y too. And there was just a lot of stuff going on. First off, we didn’t have much equipment to work with. But a ton of boxes to open. So this coworker and the manager kept giving us boxes but we didn’t have anywhere to put anything. Then this coworker is working the weekend by herself and she kept complaining that “she didn’t want to do any work tomorrow.” So she just kept pushing boxes to us and making us work faster then we were actually able to. Then about half an hour later the manager came up to us who hadn’t been around us all day and said we had to work faster. So this coworker basically threw us all under the bus for her own benefit because she doesn’t want to do any work tomorrow. I just felt like her telling on us was unnecessary. I feel like you should only tell the managers on people when it’s something serious and not just to benefit yourself. Not to mention she was also using her phone a lot. So I became visibly annoyed and started stacking boxes. I feel like she’s all butt hurt over me being hostile towards her when she’s the one who told on everyone when we couldn’t even do much work. She doesn’t want to do anything on the weekend so she’d rather be sent to the sales floor? Because that’s where she will be working if there’s nothing to do. And I doubt she wants that. I’m trying to figure out if I should apologize to her through text or not. I think she really could tell I was annoyed at her. Although it wasn’t just her I was annoyed at.