A text my sister sent me, came through on a text thread I had with a friend. 2 people have no connection with each other.

My sister, mom and I have an ongoing group text. My sister sent an image on that thread, but instead of it showing up on the Sister/Mom thread, it appeared on a text thread I had with a girlfriend. My friend and sister do not know each other, there are no connections between them. They don't live in the same state and didn't know the other existed. When the image meant for the Sister/Mom thread landed on my girlfriend thread, it started a group chat between me, my friend and my sister. My friend messaged me separately asking who this 3rd person was that appeared on our thread. I have the iPhone 12. Years ago, I can see there was an updated that may have had a similar problem, but I'm running iOS 17.4