What I can see from this, the girl in the white is going for the disc, and only the disc, not initiating any contact.
Any movement towards a legally positioned opponent (either their stationary position, or their expected position based on their established speed and direction), that results in unavoidable non-incidental contact.
All players must attempt to avoid contact with other players, and there is no situation where a player may justify initiating contact. “Making a play for the disc” is not a valid excuse for initiating contact with other players.
This contact occurs after the defender has already made it to the spot she wanted, made a play on the disc, and is in the process of landing.
This might be true but couldn't the same be said of the defense? She could have avoided contact as well, right?
To my eyes it is not clear which player accelerated or changed direction last for 2 reasons.
In my opinion she should be able to complete the bid without contact occurring, this includes landing and any subsequent motion. This would be a different discussion all together if the defender had landed and then contact had occurred.