Is my ipad or iphone hacked?

This is bizarre. Anyone have insight? Not even sure what to Google. Recently I got a FaceTime call (on my phone, at a restaurant) from a guy who I did not know, but the incoming call showed it was a number I recognized (my sister), but it wasn't from her. Then just now, while I was face timing with my sister, a weird photo came in a text from her # but she didn't send it to me. This time I was using my wifi at home on my iPad.

Any insights? Was something hacked? It happened on both my iphone while not using wi-fi and on my iPad while using wifi.

TIA