Planned a trip with new friend, then she said her friend invited herself to come..

I met this girl on bumble in Nov. We planned to take a trip to TX in May. I got a feel for her, she’s someone I would be comfortable with going out with so I was down. I saw her Saturday, and she basically said that her friend invited herself on our trip. Mind you if my friend did that, I wouldn’t have brought it up to the friend I’m actually going with on the trip because she wasn’t originally invited. Plus, this is a trip for me and my new friend to get to know each other and memories along with getting more comfortable with each other. So, she asked me would that be OK. I politely said no, because it’s our first trip and I would like for it to be us. And I don’t want I feel like the 3rd wheel because you’ve known the other girl for years and we are still getting a feel for each other. If we had some time under our belt for the friendship sure .But, then in my head I was more open to it because it would be a cheaper trip split 3 ways. I honestly, think that was just an inconsiderate, because we talked about the trip being me and her. You felt ok with asking me, instead of telling her no because the plans were already made. Planned outfits together to coordinate and all. It was def giving a TWO GIRL TRIP. And I feel like she has an attitude, because she hasn’t answered my messages about a plan we made later this week for Galentines. But I feel like if that’s your friend you would have made your own plans. I don’t know your friend, she could be a liability, we as women are going to a different state, I don’t know her habits, I don’t know how she is when she drinks, don’t know if she’s one of those ones where she brings no funds to a trip, so many other things. Am I wrong?