Proper etiquette around someone who stutters?

Proper etiquette around someone who stutters? Hi all, So I was talking to someone yesterday who I had met for the first time and she has a bit of a stutter. I of course don't mind at all, but my question is this: when someone is stuttering and you know the word they're trying to say, is it appropriate to wait until they finish, or ask the word in a polite way (if you know what word they're going for)? I'm honestly not sure what they are more comfortable with. Any thoughtful answers would be appreciated. Thanks!