...I don't know what to tell you about the sister thing.
This girl sounds like a perfectionist, and like she is very stressed out, and not able to open up, and romantic relationships aren't her priority. Any potential jealousy issues at play here will stem from deeper issues she has, in general and there's nothing you can do about it. She will work on them when she's ready. As an INFP.... If I had an ENFJ sibling who was so close in age - especially younger - I bet I'd be jealous too, lol. especially during high school. But you have no way of knowing. It's not your problem.
I understand not wanting to let there be a rift, not let things go unsaid, but it seem like she isn't willing to say much more. It's her right. I'm sorry she's (from your side of the story) not mature enough to be more open. What I would do is write her a letter and give it to her on the last day before her trip. Not being pushy, or needy, or asking for anything. Just stating that you felt a certain way about her, were confused because blabla, didn't mean to pressure her, just hope she has a good trip and that you'll be there if she wants to talk or reconnect later. And let it go.
And as an INFP if someone did that for me, well, it would mean a lot. Words to hang onto, honesty about feelings, the chance to be sentimental in private, and the power to process it in my own time. Mostly, just knowing how people feel/felt is meaningful to me, even if just for closure.
This girl sounds like a perfectionist, and like she is very stressed out, and not able to open up, and romantic relationships aren't her priority. Any potential jealousy issues at play here will stem from deeper issues she has, in general and there's nothing you can do about it. She will work on them when she's ready. As an INFP.... If I had an ENFJ sibling who was so close in age - especially younger - I bet I'd be jealous too, lol. especially during high school. But you have no way of knowing. It's not your problem.
I understand not wanting to let there be a rift, not let things go unsaid, but it seem like she isn't willing to say much more. It's her right. I'm sorry she's (from your side of the story) not mature enough to be more open. What I would do is write her a letter and give it to her on the last day before her trip. Not being pushy, or needy, or asking for anything. Just stating that you felt a certain way about her, were confused because blabla, didn't mean to pressure her, just hope she has a good trip and that you'll be there if she wants to talk or reconnect later. And let it go.
And as an INFP if someone did that for me, well, it would mean a lot. Words to hang onto, honesty about feelings, the chance to be sentimental in private, and the power to process it in my own time. Mostly, just knowing how people feel/felt is meaningful to me, even if just for closure.