My girlfriend drinks a beer or two every morning at breakfast, do you think this is an issue?

I've been dating her for about 4 months. During the whole time I've known her, she will drink a beer or two at breakfast. During the rest of the day/evening she's actually not much of a drinker at all. I've seen her plastered maybe twice. She says it's a habit she picked up in her sorority (she graduated about 5 years back) and she's done it ever since. She says it's kind of just a quirky thing she does. She seems capable of going without her morning beer if there isnt any in my house and she slept over, but if we're trying to pick a brunch place or something, she'll definitely make sure we head to a place that serves.

For a while I was wondering if she was a closet alcoholic and maybe sneaking drinks, but I can say without a doubt that's not the case unless she is slamming shots from a flask in the ladies room. And I have never, EVER smelled alcohol on her breath, unless she's been having a drink in front of me (with me). And she doesn't have normal symptoms of over consumption, like slurred speech or hangovers. Plus why would she do this extremely weird thing (morning beer) if she's just going to hide the rest of her boozing? I mean I could understand an evening drink or three a lot more easily than a morning one.

Anyway I'm just wondering if I should delve further and what your thoughts are, or if you think she has a problem, how to surface it...I mean I like the girl a lot but I'm not ready to be in some weird codependent shit you know?

tl;dr: gf drinks a beer for breakfast, but seems otherwise normal, is this a problem?