Alethea was used to the scent of the unwashed masses, and worser things; rotting flesh, vile brews of poison, the final evacuation of the body's waste upon death. It was a testament to both her rough and impoverished upbringing as well as her preferred occupation that she was unaffected by the current stench.
Alethea turned sharply on her heel when the last head was taken away from the sight of the crowd; to be tarred and left on a spike, no doubt. She stepped almost directly into Queen Kaelyn's path, Pennywise whuffing a warning of the hurrying woman's approach.