What is Peyton refering to when she says "you made fun of my mom's death" to Brooke?

Hi everyone! In season 4 episode 15 named "Prom Night at Hater High" Peytons says to Brooke when they fight: "you made fun of my mom’s death Brooke. آپ knew her, آپ cried with me when she died and now آپ use her as a مککا, عجیب الخلقت line for a joke to hurt