I know a lot of people here will recommend the "just do it" mentality. The method isn't bad but I would like to give you an easier alternative:) Showing vulnerability is a key aspect of a true relationship. Just throwing yourself in there isn't, in my opinion, the way that could guarantee a good outcome, although one such reality might happen everything is possible! But try to you know, play it relatively slow and open up about other things that gives her a signal that you trust her. If she reacts well then go for it! Tell her that you have a stutter and that you hope it doesn't affect your relation in a negative way. But it's up to you in the end, your the one who can tell what's the best method to with! Good luck man!