Luckly, Tanjiro's dying at a slow pace. If he died like the one that pissed off Muzan in the alleyway, he would be a bucket of human sludge right about now. But then again, Muzan might have given her a lot more blood compared to what Tanjiro have.
I bet the meds is still taking it's time to kick in and by the time she reach the scene, cured and buff everyone, she will be KOed and turns back into human. Muzan is going to be pissed and will try to convert Nezuko again into a demon but by that time, the sun has risen and he will burnt into a crisp. It's either that or somehow Tanjiro kills Muzan using the final technique he somehow learns in his near death state.