Hi Seasons,
We recreate the familiar, not the healthy. You're trying to break away from a lifetime of habits/behavours/interactions that have been reinforced thousands and thousands of times. That's extremely difficult. Changing is extremely difficult even when we want to with all our heart and soul.
And, she's your sister!! There's an inherent bond there that is really hard to break, to give up on, and to let go of. You sound like a really good person, so of course it's going to be hard for you to do that.
I've always thought that sibling bonds are much deeper than anyone, the professional community included, gives them credit for. They run very, very deep ... after all, you share the same DNA, which is something even your parents don't share. Your blood is very much their blood, literally (even if it's a different type). Of course you're disappointed that she doesn't call -- good or bad, she's your sister; it's hard to accept the idea of not having a sister, and hard to give up on the picture of the sister you would like to have. Very hard.
I know this a little, because my sister is a good person, but she's not very emotionally available. I know she loves me, but she's not the kind of person you get close to. Sadly, she is my only living relative (other than cousins et al), the only member of my immediate family left. Although we talk more since my dad died last fall, it's still not very much, or at all familiar -- as in, not anything like with my girlfriends. I'm already lonely for other reasons, but this makes me feel especially lonely, since she's my sister and we're "supposed" to be close, and she feels so distant. She doesn't live all that far away, a little over an hour; and while she easily comes to my town once a week for her dog training classes, she never comes to see me. Oh geez -- there go some tears. That's how it was/is with her and my mother (when she was alive) -- they paid more attention and were kinder to their dogs than they were to me. I mean that quite literally. Didn't know that was going to come up!!
I also know about sibling bonds because the opposite was true of my brother. He and I were very close, and I essentially lost him when we were in our 20s (he was in a mountain hiking accident and was severely damaged for 20 years, so he was not the same person at all; couldn't talk or communicate.) I learned what I know about the depth of siblings bonds when I lost him.
Anyway, I know these things are difficult. Try just to pick up on things as you have, but don't judge yourself for what you want or feel. Your feelings are just your feelings, and you'll feel better (!!!) if you just let yourself have them. See # 4 below.
In fact, in the spirit of my brother, here are his "commandments." I've saved them all these years because I think they're just great:
(1) don’t believe anything that doesn't make sense at gut level.
(2) Mind your own business.
(3) Want what you want, not what you think you want or ought to want or try to want.
(4) Relax.
(5) Hop, skip, and go naked.
...I guess we could keep a few of the old ones.
See what I mean? He just made life fun and interesting.