Well, she only got in if someone decided to allow her to break the dress code. They are pretty strict about having shoulders and knees covered.
I searched out some pictures and it appears she was wearing a short skirt, a tank top and at times a cardigan over the tank top. So maybe someone decided that even though the skirt was a little short, they could allow her in.
Now, if she had been denied entrance and kicked up a fuss, that would have been rude. But it appears that whoever decides on whether visitors are appropriately dressed did allow her in, so she didn't commit a faux pas.