Welcome to the SR family!
Do you have a local Alanon group for face to face support? I find that hour of calm at a meeting helps keep me grounded.
You are right that giving an active alcoholic money is never a good idea. Active alcoholics are masters of manipulation, deceit, drama, and denial.
By sending her money, you would be preventing her from experiencing the consequences of whatever drinking has caused lately. By helping her indirectly and paying her power bill or buying a grocery store gift card, you are still preventing her from experiencing her consequences.
Her poor choices = Her consequences.
Sometimes by trying to help the active alcoholic, we are getting in the way of them reaching their bottom and finally reaching out for real recovery from their addiction.
I know how it feels to have a loved one addicted to alcohol. You are not alone.
The three C's of addiction help me keep my perspective about where my responsibility ends:
I did not cause it
I can not control it
I will not cure it
Your neice has been to AA. She knows where to get real help when she is ready.