The problem with only looking for single women is that many ladies may put themselves down as being single because they are - at the moment. However, they may, in reality, be separated, divorced or widowed. They're not lying, it's just a matter of interpretation of the singleness. What's really important is that they are single at the moment, registered with your dating agency and want to meet someone for a new fun.
In the same way did you really mean that you only wanted to meet single women in the truest sense of the words? Just be sure that you have read the questions for what they are and have thought about how others might view themselves as single girls. It's certainly not unreasonable to expect people to possibly describe themselves as single when they're not in a relationship at the moment. That is ... girls to meet ....