Would you agree that she was making sure I didn't get the wrong idea?

yeah i think she was just making sure that you didnt jump to conclusions when you read them. i had a friend who use to do the same with his girlfriend [my best friend] b/c girls would constantly post comments so he would just let her know that he didnt know them, and i could tell he was being sincere. So if ur gf is trustworthy, then dont worry about myspace! :) however, if she is known for being 'sneaky', then hmmm idk. lol but yeah i say you dont worry about it!! :)