You are already on the right frame of mind. Just give her space and let her go at her own pace. Also, if you never met a stutterer before, it will be kind of weird to experience it for the first time. You might have the urge to laugh, but don't. You might feel weird about seeing a face stuck in repeated motion, just try to control your expression. Treat her normally. Also, don't expect her to be what she was on chats. More than likely, she will be nervous, shy and speak far less than she would have on chats. Try to relax her, and let the ice break itself. It will take a few meet ups for her to relax around you. The key is to make her feel safe. The moment she realizes you aren't a threat, she will open up. Good luck with the date!