Every single person carries their childhood into their adulthood. It is how they choose to deal with it that defines who they are.
And if they never choose to deal with it, then they are doomed to allow it to define them.
If she ever truly wants to move past this she will stop drowning her grief over the childhood she didn't get in alcohol and deal with it. She will stop trying to blame others for her own unhappiness. And all of that is hers, not yours.
This is who she is right now. Harsh? I don't know. I think it's more loving to see someone exactly where they are and to accept them that way. Accepting them does not mean you have to forfeit your own time and happiness to their issues and the things they aren't getting past. Harsh is demanding that someone else change in order to make you more comfortable. I don't see that in you.