Meaning of 漂漂亮亮地参加晚会 I saw this sentence on a textbook: 


  漂漂亮亮地参加晚会


Without more context information, what is the translation of that sentence?

I think it has a meaning of "(a girl) dress up beautifully before going to a party", but I'm not quite sure.
Your understanding is correct. This sentence is equivalent to

打扮得漂漂亮亮去参加晚会