Numbers - i think it's great you are trying to be so supportive of your sister. she's lucky to have someone like you .

just my opinion, but please don't change your behaviours to accomodate her new diagnosis. this means that if you have always switched things off at the walls because she asked you to, just continue to do so. but if you have never done it before, don't change and start doing it - it will probably reinforce her behaviours, and she's the one who needs to tolerate distress and learn to change.

same with checking locks and things - don't change just because you know her diagnosis now. i think she needs you to be the same sister you have always been, and evidently you are a good one.

maybe if your sister is open to the idea though, you could ask if you could go talk to her Dr with her there also? just to find out some info on how best to support her. yes, she is an adult so i doubt her Dr would make it a point to call you in, but at the same time if it is something she is willing to allow then it would probably be very good for both of you. if she would prefer for you not to meet with her Dr, then at least she will know you were concerned enough to ask.