Perhaps their introduction or 'About-Us' pages or other relevant pages could give you some background information of this specific Dating Agency, which could give you a 'good' or perhaps 'wrong' feeling about this site and their services.Also try to find out if they are a member of the Anti Scam Program.
Important is to see how your mutual correspondence is developing, about what kind of subjects you both are talking.
But if the woman starts (in an early state) with questions concerning money, for any kind of reason, than you have to be careful and you have to analyze if these questions has anything to do with the situation you and your correspondent are aware of.
One of my favorite quoted expression is: "By failing to prepare, you are preparing to fail." (Benjamin Franklin - 1706-1790) But there are also many variants, that are 'close' to swindle practices, but not (yet) labeled as real illegal organizations.
These are organizations that will use methods to keep you as long as possible as a paid customer, or those who ask far too much money for their services.
For example, some web sites have over 20.000 profiles, however this is not a reason to find any scam inside this Agency, it only gives you an impression how many profiles you can find on the 'entire' web.