I think that's normal for you to feel that way, but it's not going to help you.
The bottom line is, she is an alcoholic. Think of it this way, if you were drinking "7-8 cans of Bavaria lager each day no matter what", would you be worried about whether it was xmas or anyone's birthday? Probably not.
You can let this kick you around the block or you can accept that this person you are involved with is in active addiction and norms do not apply. If you are going to be involved with her you are going to need to detach from these behaviours because otherwise you will just get dragged down.
Don't try to apply the logical to the illogical perhaps.
Some good information here, in our stickies section, if you are interested you might want to start here:
https://www.soberrecovery.com/forums...c-reading.html (Classic Reading)
Also these articles:
Addiction, Lies and Relationships
A relationship with an alcoholic is not the same as one with a non-alcoholic and the more knowledge you have, the better. Of course not all alcoholics are the same, they are individual people, but there are some common threads in addiction.
And Happy Birthday!