My cat is breathing from its mouth?

me nd my mom were having a fight when my cat zara was in the room. then my mom closed the door and me nd zara were alone. i saw her breathing from her mouth really deeply. whats happening shes 6moths old, she got spayed, she didnt have any shots done yet. each time i held her she starts opening her mouth andstays near the window. now she starts to bite. why?