Friend mad at me?

[Cynthia]

So theres only about 2 weeks left of school and my grandparents invited me and only one friend (Reasons that theres not enough room for another person) to thier beach house about a 3 to 4 hour drive from where i live. I've decided who to take within the 4 friends. 2 of the friends have plans on that week and not able to go, so they didn't mind the friend i chose. One of the newer friends that joined the group, got mad. Making a status on facebook saying "when your friends makes plans infront of you and you don't invite them". I told her that i can't take her because there is only space for one other person, she ignored me and apparently starting telling everyone my personal things (Don''t want to talk about). I got fairly mad and her and told her why she told everyone my personal life, she said to get you back for not inviting me to your beach house.
Help?