Get a box of cat treats and walk around shaking it. and if that don't work try putting some tuna down somewhere where you don't step in it. If it disappears, then you know the cat is still o.k. and just likes to hide.
Sit down and don't even THINK about the cat, after putting out a dish of food (Fancy Feast is usually irresistible to a cat, especially fishy flavored). The cat will likely at least come out and eat, so you'll know she's alright. If you do this often enough, she'll learn you're trustworthy.