Human female here lol. If you feel more at ease telling her beforehand, do that. However if I was in the woman’s shoes and I was vibing with a guy via text, I wouldn’t be put off by a stutter. I already know that you’re a fun person to talk to, and I’m guessing she’s seen pics and likes what she sees (let’s be honest that in this day age this happens). So if I were her, I really wouldn’t be put off by a stutter. Yes, I know I’m biased bc I also have a stutter, but I don’t think I’d think differently about someone whom I liked over text who had something a little different about them in person that wasn’t something problematic. (Like you aren’t the person you said you are, or you once dated your sister etc.) Whatever you decide to do, my best advice is this: just be confident and thoughtful. Those are the qualifies women, including myself, respond to the most. And if the other things match up well too, you’re in for a good time. Good luck!