With the inquiry with ex-H, it sounds like your sis had her heart in the right place and was doing what she felt was looking out for you, even if her POV may be tainted some with her own bad experiences. Little do they realize how their best intentions can backfire.
Fran, like how you can't control H's actions, you can't control sis's either. With "I" statements, let her know you appreciate her trying to watch your back, but express how you hope what you tell her you is kept between just the two of you, then let it go. She is the one that has to make the choice on whether to respect your wishes or risk pushing you away. On your end, you can be more mindful on what you wish to share with her until you know what level of confidence you can regard her with.
