I had a similar interaction with my sister while talking to her on the phone during college. I don’t remember the specifics of the conversation, but I do remember crying and going for a 2 hr drive to the middle of nowhere in the middle of the night and reflect on life. More than the words, I felt betrayed that my sister was insensitive in that one comment, when growing up she was my biggest champion and even a crutch when speaking in public. I don’t know how close you are with your sister, but I was and still am close with mine. I reconciled that she likely wasn’t of clear mind and it was the first and only time so far (it’s been over 10 years ago). I never brought it up to her, but it is a testament how words can hurt when coming from people you trust. As for advice, if you trust her, consider if it was a one-off and let it go. Keep trying to share your frustrations with your family and share your stuttering experiences. Maybe in these casual conversations, they aren’t defensive and just listen. Even telling them, “hey, I need to vent for a minute, so just listen”, may help. For the record, I have also limited my Spanish because of stuttering, so I know exactly what you’re experiencing.