My FMIL is a major alcoholic. To give a little background she had gastric bypass in 2009 and about one glass of wine will get her drunk, but she normally drinks a whole bottle or more. I am worried because every time she is drunk she gets very verbally abusive towards her husband and her son (my FI) mostly telling them how there worthless and stuff like that. I am terrified she will do this at our wedding and ruin bolt mine and my FI day. We have tried to get her help but she is in denial about her drinking and we do not know what to do, since his dad just chooses to ignore it.