My husband's reaction to an alcoholic father and 5 alcoholic uncles that kept the entire family in turmoil was to never take a drink for fear he would end up sleeping in vomit like they did.
No one in my family ever drank very much because it gave us all terrible headaches.
Reminds me of why my Dad never took up smoking. Said he got to hear his Dad cough up a lung until about 10:30 every morning and decided it wasn't for him.
I'll be praying for your niece.