In my experience, it seems like girls find stuttering kind of cute. It’s something you struggle with, but still managed to come this far. I think you just need to push through and ask her out. Look at it this way, if she reacts in an insensitive manner, maybe it’s not a good idea to date her anyways. My stuttering is really bad and it’s really easy to fool yourself that you are in some ways “inferior” to other people, which absolutely not true. Own your stuttering with confidence and ask her out!