Am I overreacting for feeling uncomfortable about my friend’s brother being involved in our trip last minute?

Hi everyone, I need an outside perspective on this.

I (24F) had planned a New Year’s Eve trip to Alibaug with a close female friend. We booked everything in advance and the understanding was that it would be just the two of us.

Initially, after booking, her family was worried about the trip and suggested that her elder brother (who lives in Mumbai) should come with us throughout the trip. I clearly told my friend that I’d be uncomfortable with that and even said we could cancel the trip if that was necessary. After this, she reassured me that it would just be the two of us, so I mentally settled into that plan.

Now, just two days before the trip, she told me that her brother will be picking us up from Mumbai railway station and dropping us till the Gateway of India ferry point for Alibaug. I’ve never met her brother before, and this was not communicated earlier.

When I expressed that this sudden change makes me a bit uncomfortable, she said there’s “no need to be uncomfortable” because he’s her brother and he’s a good person.

To be clear:

•	He is not joining the trip, only dropping us

•	My discomfort is not about him specifically — I’d feel the same even if it were a girl. But now that he is a guy, the discomfort is even more.

•	It’s mainly about a last-minute change after I had already expressed discomfort earlier and was reassured otherwise

I value this friendship and don’t want to create unnecessary conflict, but I also don’t want to ignore my own boundaries.

Am I overreacting for feeling uncomfortable and wanting to say no to this? Or is this a reasonable concern?

Took help of ChatGPT.