Maybe she read something recently which she thought would help. Sounds to me like she thought it would be encouraging, but obviously didn’t come off that way. I’ve stuttered and have talked about it in relationships, to close friends and even coworkers. I think it helps to clear the air so this type of misunderstanding doesn’t happen. Sometimes my wife points out when my choice of words don’t make sense (which is due to avoidance strategies), but I know she’s not being hurtful.