Sorry Kelly, but you are now responsible for that grey and white cat. Your efforts are noble, but just because it was not the cat you were looking for is no excuse for inapropriate behavior. No cat should be released back into the "wild" without being spayed or neutered first. If she's completely feral she may be released in her familiar area... BUT ONLY AFTER being spayed/ neutered. If she is not feral it is not fair to put her back outside, she'll need to go to a place where they will find her a home.

I picked Lucas up off the street CERTAIN that his owner would come looking. What was I going to do when no one came?! put him back on the street? NOT AN ANIMAL IN MY CARE!!!!