Dribble
 

B1 picks up their dribble and the official starts the 5 second count since A1 is within legal guarding position.* When B1 thinks a 5 second violation is about to be called, B1 intentionally throws the ball off B2’s leg who is standing near by, then B1 retrieves the ball and starts dribbling again. The ball is not tipped by A1.

B1 relinquished PC, the ball legally touched another player, and B1 gains PC.

So what's is your question?

(Would the question be any different if B2 had tapped the ball with her hand, instead of the ball hitting her leg?)

Legal. Rule says player can dribble again after he loses control because of a pass or fumble which is touched by another player.
The reason he is passing it off B2 leg isn't relevant. imo

Supporting reference -(I just happened to be in my books at the moment.)

9-5-3 . . . A player shall not dribble a second time after his/her first dribble has ended, unless it is after he/she has lost control because of:
ART. 3 . . . A pass or fumble which has then touched, or been touched by, another player.

I'm nitpicking, but legal guarding position has nothing to do with the six foot distance for a 5-second count to begin.

Legal by rule. It can be easy to get caught up in legality vs. morality sometimes :)

Yeah, i think in context of his question you have satisfied the definition of "nitpicking." :) it happens from time to time.

Yeah, she may burn in hell for it, but I'm not blowing my whistle. She can take it up with her maker.

I thought that was the answer "no violation". I was worried I had missed something.