Well even on Legit datings sites can be fake profiles, So saying why not is not a great encouragement. Just because a profile pic with details that's sounds to you as good as you think, Don't mean its really them. However, if you are lead to start talking to her, then Maybe pray for God's will in it first. I know you can trust God to give you the right words to say. Pray about it. No Offence, you asking people on here is going to get you even more confused and mixed views as to what to say, and possibly no encouragement. The best thing for you to do is, Start off with a hello, how you doing, nice to meet you. and maybe ask her to show herself on webcam? Because anyone can grab a pic from google or other internet and make up a profile to pretend that's the person. Sorry it happens!. If she makes excuses that she cant go on webcam, Not all the time, but most young people has webcams, and if they are genuine enough they will show themselves on cam, at least that way you are getting a bit more security that you are talking to the genuine person. But those who fake will make all sorts of excuses.
Im not saying that the person you met is not real, but just giving you the taste of the real world of fakes who loves going on the dating sites to mess and troll with innocent people. So be careful for those reasons, but the best thing you can do is pray about it, make sure its his will for you to date, for you to meet and have relationship. that why you will know for sure. and know what to say too.