I hope you do get in touch with your sister, i had a sister that killed herself and i reminese as to what it would be like today if she hadn't. I do have 2 other sisters, but we were never close as adults should be. Losing a sister is one of the most painful thing I've ever experienced, I don't wish that on anyone. That is why im thinking that your sister is trying to reach out for you to help you even after she made the mistake with the dog. If not, there isn't much you can do to get closer to her but you still have the chance to try, if it works thats great, if not, then you can say you at least tried. good luck