My sister is bailing on me right before our trip

I (21F) booked a trip with my sister (19F) about a month ago. Before booking it, I obviously talked to her about it first. For context, she’s a college student with no part-time job, so all of her money comes from my parents. They pay for her rent and basic expenses. She’s been “looking” for a job for months, but not very actively, so she never found one.

On the other hand, I have a paid internship. I don’t make much just enough to cover my rent and daily expenses without asking my parents for money.

When we booked the trip, she chose the destination and agreed to everything. I paid for the whole trip upfront because she didn’t have the money at the time, and I didn’t mind. She told me she’d pay me back once she got a summer job.

Now we’re only a few days away from the trip, and she suddenly bailed on me 😄 saying she has no money left and can’t afford it anymore. And I’m PISSED.

If she had told me from the beginning that she wasn’t sure she could go, or that the trip depended on her getting a job, I NEVER would’ve booked it. Or I would’ve waited until she actually had the money so we could go together later.

I completely understand being broke, I was in the same situation last year. But what annoys me is that she knew about this trip the entire time and still kept spending money going out with friends, buying food outside, etc. She knew she was running out of money and still acted like the trip was guaranteed.

What makes it even more irritating is that she’s been staying at my place for the past week and acts as if nothing happenned or is happening, makes me feel crazy. When she told me she couldn’t come, I asked, “So what am I supposed to do with the trip now?” and her response was “Well, I don’t know what to tell you. I don’t have money. Just go alone like you did last time.”

That response genuinely pissed me off because it felt so inconsiderate and dismissive, like “Not my problem anymore.”

I don’t even mind going alone. What hurts is being treated like my time, money, and effort don’t matter.

Then when I asked her, “Why didn’t you tell me from the start that the trip depended on you getting a job? I wouldn’t have booked it otherwise,” she immediately got defensive and said: “I DID tell you that if I didn’t get a job, I wouldn’t come. Don’t start.”

Which honestly feels like a straight-up lie, because why would I spend money I barely have on a trip that wasn’t even guaranteed to happen?

What confuses me even more is that she got an interview not long ago, and when she thought she might get the job, she suddenly started saying, “Yeah, I’ll come if they hire me.” But even that made no sense to me because the trip was so close that she realistically wouldn’t have had enough time to work long enough to even get an actual paycheck before the trip anyway.

That’s why I’m frustrated. Her whole thought process just doesn’t make sense to me. It feels like she kept acting like the trip was still happening without actually thinking through whether she could realistically afford it.

At this point I’m just done with all of it.