What can one say other than Bless Her Heart. After all, it's only the national anthem, and the most watched event of the year.

From Merriam-Webster:

During her rendition of the national anthem that preceded the [Super Bowl] game, Christina Aguilera botched the lyrics and never sang the words "O'er the ramparts we watched / Were so gallantly streaming." She instead improvised a line that closely resembled a previous line in the song ("What so proudly we hailed / At the twilight's last gleaming").

A rampart is a wall that is built to protect a castle, fort, or city. Francis Scott Key, who wrote the poem that became the "Star-Spangled Banner," was observing the British attack on Fort McHenry during the Battle of Baltimore in 1814 when he wrote the famous words.