I feel like I could have written a lot of your post. I have the same situation: my sister is a heroin addict, my mother enables her to continue using and at this point spends the entirety of her life completely enmeshed in my sisters ongoing drug-related drama. My mother also pays little attention to me. How could she? She is completely consumed by my sister. Whether it's bailing her out, getting her cars to use or retrieving cars from impound, making excuses about why she can't ever get or keep any job ever (even in an industry that is extremely felony-friendly), court appearances, complaining about how the system is out to get them, and on and on and on. It never stops. When I first came here I was at the point where my anger at both of them was having a visible negative impact on my life and my personal relationships. Anytime I engage with them I always end up feeling worse, so I have had to limit my contact not only with my sister (who basically rarely contacts me at this point once I stopped helping her out of her various consequences), but also with my mother.
It hurts to not have as good of a relationship with her, but what I am starting to accept is that our relationship wasn't ever that great to start with because it always revolved around my sister's actions and chaos. At first I tried to maintain the same rate of communication with my mom and just not continue the conversation when my sister came up, but it turns out almost everything she has to say is about my sister or situations that are a direct or indirect result of my sister's actions. So I have started to limit my contact with my mother. It was really hard at first to greatly reduce my contact with her, and it still is, but almost immediately I began to feel better about myself, my life direction, and where I'm at. I'm spending way less time worrying and investigating and stalking my family online, etc. and much more time fostering relationships with people in my life that are healthy and make me feel healthy and good about myself.
This went on much longer than expected, but basically I encourage you to allow your sister to make the decisions she makes without getting involved, but also to pay attention to how you feel when you engage with your mother, as well. Just as your sister will continue her path as she sees fit, so too will your mother. Your job is to make sure that you and your kids are okay regardless of whether either of them chooses recovery or not.
Keep posting and reading here, it really does help. I'm sorry that you're in this situation, but you're not alone anymore.
