No spoilers, but her questline explores this a little more, and there's a few genuinely sobering (pun not intended) lines about it and why she drinks and how she feels that you can get out of her.

She's still my second least companion mind you, mainly because her character for 90% of it is still what you describe, but there are some interesting bits.

Big spoilers for a line about her alcoholism here. There's a part later in her quest you can talk to her about why she drinks and what she's lost throughout her life, and she says, paraphrasing "sometimes I think I'll reach for a bottle and pick up a gun, and it'll bring me the same comfort."