Have you talked with her about it??
Talk to her...

OP here. Thanks. My sister does initiate contact with me as well. It's definitely mutual. I think we just have different ideas of how spending time with each other should go. She has a much stronger sense of family obligation than I do, where family obligation means spending time with relatives even if you don't like them, and I'm afraid I may be in that category.
I might be wrong, but I suspect my sister is actually a cool and interesting person - just not with me. We had a rough childhood and were played off of each other, so that definitely didn't help.

OP, maybe she likes the idea of having a sister but then the reality is you both don't really "click." She also may be emotionally stunted. Why don't you hang back and see if she initiates with you?

I felt like I was making all the effort with my relationship with my sister. She is always making mean comments, never offers to help, never makes the effort to visit or spend time with me. I stopped making the effort and we haven't spoken in 8 months. Clearly, it was a one way street.

Also, my parents are exactly like 1:16. Especially my mom likes to pretend like she has these great relationships when in fact she doesn't and it feels like as long as she gets to tell people she came to see us and/or post a picture on FB, she is just checking it off the list. It is nothing genuine.

My parents are big into being able to say they've "gone to visit the kids" but when they DO visit us we have 3 or 4 meals together of stilted, uncomfortable conversation over the course of a week and that's it. They just want to be able to say they've done it. Maybe your sister's the same way.

Are your parents still alive?

Holy cow I could've written this! I'd say you're feeling is correct, and there could still be some underlying subconscious competition for her to hang out with you in order to please your mom. If you are initiating these times together, stop and wait for her to. If she is, don't feel obligated to get together every single time she asks. She's not truly making you a priority, so you don't have to do it for her.

Cool story, bro.

We live quite a distance away, so it's not trivial to get together. I make an effort in part because she's previously expressed that it's important to her that we have a relationship, and partly because she does make an effort to come see me as well. But when we're together, she doesn't ask me questions about my life and we wind up talking solely about her life and her interests, and even those conversations I'm initiating. And she just doesn't seem very enthusiastic about seeing me or doing stuff with me. Over the years she's made a number of negative comments about my lifestyle, job, my lack of religious practice, etc. She doesn't do that anymore, which I appreciate. She's very polite now. But I feel like she doesn't actually like me and is just spending time with me out of some sense of family obligation. I'm not very interested in that. We both have spouses, good friends, and communities we're part of, so I'm not sure why she'd want me to be a big part of her life if she doesn't actually like me. Apart from the fact that she's been pretty nasty to me over the years, I do like her. We had a rough childhood in which my mom pitted us against each other, so I don't blame her for having some negative/weird feelings about me.