@Kaarme
You're right, she was indeed arrogant. She saw the stats and believed that Mother could be defeated by just showing up and blasting her with magic attacks and she assumed that she had the resources to deal with whatever was thrown at her. I mean, she is immortal and can teleport, what does she have to fear?
I also don't blame her for getting trapped. It's easy to set up a trap for someone, but it's a lot harder to plan for getting trapped and dealing with it because there are so many ways you could get trapped. Everyone has blind spots, and for me it's far more unrealistic when you have characters who somehow see through all the traps thrown at them. As a spider, I don't think she expected to get caught by threads and in this instance, she was caught by a thread technique which she wasn't aware of, so this trap isn't something that she could set up herself as she has never seen nor used this skill before.