Beating on newbies doesn't encourage them to work harder, it generally makes them not want to do it ever again. Sounds like a douchebag. You should find someplace else for your sister to train.
Yesterday, after reading the replies, I went down to the gym personally and had a little talk with the coach. Apparantly, at his gym, it was "common practice" to do first spars like this because it will "toughen them up and encourage them to work harder". I tried to inquire further and basically got told that he was a former professional kickboxer and boxer, had run a gym for thirteen years now, and knows excatly what he is doing.