Heart wrenching but no details. Does not even answer a single interrogative that I can see. Who, what, when, where, how .... ok her sister was shot that’s how. Could be anybody, a hoax even.
Actually she said “protestors” shot into the crowd, hitting her sister. You can infer that her sister was either there to protest too or was a bystander. Ether way, the thugs decided it would be good to fire into a crowd, perhaps to create greater chaos, who knows.