I like your idea. Flipping this around, maybe us craft beer drinkers could have a huge C printed on our jumpers and jackets. Folk would then instantly be able to tell we're craft beer drinkers and give us the respect we deserve. The 'C' stands for craft.
But to have a level that high at 11am either indicates she hadn't stopped boozing until very very late/early or had a utterly ridiculous amount the night before. 3 times the limit is very very high.