Had a disagreement with friend, she never replied to me finally text me and is wanting a QUICK RESPONSE

This is a follow up to my previous post. Me and friend were supposed to go on trip, we recently met about four months ago and clicks so well we decided to plan a trip. She said that her friend basically invited herself on our trip. Then she proceeds to ask me is it cool if she comes, I said no. Because, I do not know her friend and that would be basically another liability. I don’t know her habits, I know nothing about her. And I rather not be the third wheel which I would be because her and the other girl know each other. Plus I’m not interested in being friends with someone who feels so entitled to invite themselves on a trip no one invited them on. So, we had plans for this Friday and I sent her the link but she did not get back to me until today. And then she sends a second follow-up message. I knew she said she was going on a trip with her friends but I didn’t remember the date. Mind you, this is a trip she took off work for and told me about a month ago so this isn’t a trip that just slip your mind. Plus I think it’s inconsiderate she’s just getting back to me. She answers pretty quick and I’m not mad she had other plans at all, that’s not the issue. This is just another sign of inconsideration for me . The first one was letting your friend invite herself on the trip and now this. I was going to be petty and take my time to reply to her or send a passive aggressive message basically saying“it took you two days to answer me, but now you’re rushing for a reply”. But I’m trying to not be that person. This is the first friend I’ve had in years that I do enjoy, but I’m distant from making friends because nobody understands consideration and principal these days.Because why does she think her messaging me is more important than when I messaged her and she should get a quicker reply? She’s cool but the whole trip thing and ignoring my message PMO honestly.