It looks to me like she's humping in one part of the video, but regardless, the fact is the PUPPY is trying to control the situation when YOU should be controlling the situation. I would think that YOU would know that.She's not humping. She's standing over Sophie in a show of dominance. I would think you would know that.
I cannot believe that you would allow a Doberman puppy to play like that with a small dog. It's all cute fun and games right now, she's only 7 weeks old. I can assure you that when she gets bigger, it will be far from cute; and can be downright dangerous.