It's good of you to think like this. I think it's a valid concern. For me, basically any sound I can form in my mouth vs. my throat is easier, which opens the door for a lot of things. But, it's definitely important that you both like the name. Try to have an open discussion about it with your gf. She likely won't know the stress/pressure that comes along with stuttering. Hopefully you can find a name you both like.