Your Mom sounds like she is frustrated because she doesn't understand why you're stuttering. I'm not defending her, but I've found with older generations, if they don't understand something right away, they feel it's made up or not real. They're scared because they've never encountered it and don't have an answer for it. That's just my take, though. It doesn't make what she said any more true. It IS totally possible for you to start stuttering one day. A stutter can come out of no where. That's one of the reasons stutters are so hard to understand, even for those who have stuttered for a long time. I suggest finding a speech therapist, if possible. If not, there are plenty of studies and information online for you to read, to educate yourself. I know it's super upsetting, but we are here for you!!