Let me clarify what I meant. The BR, despite having lost her balance, was doing what she was supposed to be doing. She did not commit an "act" of interference, which, to me, means doing something she wasn't supposed to do. Had she darted left or right, threw up her hands, swatted at the ball, or something else along those lines, I would then have INT.
However, despite the fact that she embarrassed herself on the field, she did nothing wrong. I won't call that INT unless I see her do something she's not supposed to do.
If she was that far away from the 3' running lane, the catcher should have had enough time to make a good throw. I blame the catcher on this one.