I too think you did the right thing. After all, if the bottle of whiskey was a present for someone I assume she would have said so, instead of accusing you of judging her. That smacks of a guilty conscience to me.
If she has a problem with drink that hasn't yet got out of hand, your remark might just pull her up. If she is an alcoholic, sadly she will only ask for help if she herself one day wants to stop drinking.
Don't lend her money again - you don't know what the money goes on, and does she pay you back? I don't think you mentioned that.
Next time she complains of poverty, offer to help her make out a household budget. Lots of younger people have absolutely no idea how to go about that,
I would still invite her and the child for the odd meal, for the child's sake.