Because a true sociopath who was also a witch would, after having a five-day vacation ruined by the possible death of her beloved cat, gather more personal effects from your office tomorrow and use them to make your son just as sick as her cat was today to teach you a lesson about making light of the whole thing by saying, "Oh, the ocelot is sad because her cat is dying" to your boyfriend in a jokey tone.
But luckily for you, this ocelot who is also a witch just has sociopathic tendencies. This prevents her from tossing a curse so bad that you get to sit there and watch, terrified and helpless, while your kid dies in front of you. Because it isn't the kid's fault that you're a stupid little bitch whose mind and soul have all the depth and resonance of a very small mud puddle. The kid shouldn't suffer because you're a shallow, petty twat.
And it's lucky for you that said ocelot isn't ten years younger, because she'd also punch you in the throat for good measure while she destroyed the thing you supposedly find the most precious in the world.