Two cats - how much noise could they make? It seems a bit picky to me - but you may find out she is the neighborhood complainer
They can be louder than you can imagine. A few nights ago I was going out with my downstairs neighbor and I was in his apartment waiting for him to get ready and I could hear Tibby and Corkscrew wrestling, now I can understand why he confused it for two people wrestling. But I agree with Gini see if you can make friends with her. I know my downstairs neighbor was a little bothered by the noise until I made friends with him. He really softened up after the first time he met my cats, he saw Corkscrew and just fell in love with him. He said he was a very manly cat and he really liked him. And now occasionaly he's even mentioned that when he gets enough money he'd be interested in getting a cat himself.