As with most fears, this is a silly one. For one, you have no control or influence over a relative's fluency. It's not like you were the one to pass on those genetics, so your feelings of guilt or blame are completely unwarranted. Secondly, life as a stutterer isn't exactly the worst thing ever. So what if she does have a stutter? It'll be a challenge, but then she could have plenty of other, far more difficult challenges. It's not a death sentence or anything. Thirdly, just because you have a familial line of stuttering doesn't mean she'll automatically inherit it or, if she does, won't ever grow out of it. I have five nieces and three nephews, none of them stutter, despite all of their parents and I at one point having a stutter. Don't fret about it.