It sounds like to me like she overdoes it on occasion, and it makes you uncomfortable. Can you avoid the situation; as in try to leave before she gets drunk? I would talk with her without judgement, and tell her how you feel, but not in a blaming way.
I do understand the difference between 'getting tipsy' and getting embarrassingly drunk. I hate to say to watch her intake, but maybe suggest a bubbly water in between drinks, so she is not taking in too much too quickly. I realize you are not her her keeper, and what she does is up to her, but you can control how you react. Leave the situation before it gets to be a situation!
I'm not sure what she drinks, but some drinks are stronger than others. If she is ordering mixed drinks, suggest a tall, which has more mix, or stick to cider or beer which has a lower alcohol content.
I've always said drinking is a problem if affects your health, your wallet, or your relationships. It sounds like it is affecting your relationship, so try to have a discussion with her, but not 'the morning after'!