Sydney's mother gave herself in last episode and now she is refusing to tell anything expect for Sydney and she refuses to see her - the emotions really run this episode and the way we see development from not seeing her at all until the end, when she makes one thing clear - she is not her mother. Her mother died in the car accident. That was a stunning development and the only way shew could cope with it all.
And the missions - pulling that alarm or not.. the matter how she did not trust her.. but she was considering it. Her father did not do even that..