My Cat's Viscious!

My cat is really mean to other animals even if they are bigger than her. My landlady agreed to take care of her while I go on vacation and she suggested bringing her to her own apartment instead of leaving her alone in mine. I told her she could try it but she has a cat and I don't want her to harrass her cat the whole time she's there by trapping her in rooms and hissing at it so we'll see. She's viscious!