At least one person on this thread has pointed out that it was a one-way road, so there would be no reasonable basis to say that she was attempting to make a U turn or a 3 point turn. However, I'm not sure which street she was on, while Portland Ave does appear to be one-way s/b, E. 34th St. appears to have both east and west bound lanes (satellite photos show cars parked on both sides facing opposite directions). Almost certainly she was on Portland because the vehicle that her vehicle ultimately hit was on the opposite side of the street and she hit it in the trunk/rear.
Her vehicle pulled from the curb to perpendicular to the flow of traffic. She did not block the entire roadway, but her vehicle certainly was impeding traffic. While you could give the benefit of the doubt initially that she was turning or repositioning her vehicle, the longer video from a neighboring building shows she stopped in that position for 2+ minutes. The ICE vehicle with the shooter, actually drove to the curb side before stopping and there may have been other ICE vehicles that went by her in the other lane so there was a path for the ICE vehicles to go past her without initiating a confrontation. In fact, it appeared that the shooter did just that. He went around, stopped, got out and walked around her vehicle recording the situation and her license plate, likely to either record that information in ICE's system or to request local police issue a citation (or both). It appears that the shooter was about to leave when the silver pickup initiated the confrontation and everything went to hell in less than a minute.