Only she can decide if she is an alcoholic. At this point, she apparently doesn't want you getting involved with her drinking habits. I understand you are naturally concerned. But you need to allow her to draw her own conclusions about her drinking. You? Drink socially. College days are over. Getting trashed is for the frat boys.
Denial? It was, and is, powerful beyond my comprehension. I recall being in the emergency room in 2007 with fractured ribs. The ER was backed up. I laid on a gurney for about four hours. Meanwhile, my AH (who hadn't had a drink that day) started to shake, sweat, and eventually ran to the bathroom to puke.
When he returned, I said to him, "Do you realize you are in withdrawal?" His reply, "Perhaps ..." This guy was in REALLY bad shape.
His denial took him to the grave. When I walked through the apartment he lived the last 9 weeks of his life, I saw horrible devastation. But y'know what? He never actually could admit alcoholism was the root of his problems.
He went to a PTSD support group. He went to a counselor for individual therapy for his depression/anxiety. When he was terminated from his last job, he told his employer he suffered from "debilitating depression."
Perhaps he did. But his alcoholism was his undoing.
And I've witnessed denial of epic proportions. Right into the grave.
There was nothing I could do, and I almost drove myself crazy doing everything and anything. In the end, I had to step back and respect my husband's right to drink himself into the grave.