You can choose to get drunk, or not, so no excuses.
If she chooses to get drunk, as others have said she may do it again.
If I was you, her saying she was drunk would annoy me just as much as she had a choice although thay may be just my opinion, yes at the time when she was drunk she may have not known, although she knew how to do certain things ... but before she was drunk she choose to do it, plain and simple. She did tell you though if thats any consolation. Her getting drunk in the first place would annoy me a bit in itself as she is potentilly killing herslef and the relationship along with it, but I know that is just my opinion.