Texting tone changed

Anonymous
So I've been texting/chatting with this girl that I'm interested in for the last week. In her texts, she always seemed cheerful and casual, so generally just happy. Well today we hung out by going to a theme park, but this was with my 3 friends and one of her friends (It was her idea to have more people go to the park with us). After the park closed, we all went home and I texted her asking her if she got home safe, but she never responded for about an hour, so I texted her that I just wanted to let her know that I was sorry if it seemed like I was kind of ignoring her because I wanted to make sure my friends weren't having a bad time at the park. After this text, she responded and said that it didn't seem that way and she had fun, but she suddenly started using proper grammar and punctuation and just seemed cold in the following text conversations. I don't know if I'm just being paranoid or something, but did I do something wrong (she has class early tomorrow, but I don't know if that matters in this context)? If so, what's the best way to fix it?
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+1 y
Thanks a lot guys!
Texting tone changed
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