Write advice to a friend on how to determine whether his sister is showing signs of alcohol abuse. describe what to do if your friend thinks his sister does have a problem.

First, you should look for vital signs that show that she may have a problem such as:

Repeated lateness or absences
Poor work performance
Neglect of children Uncharacteristic mood or personality changes 

Other physical signs may include 
Loss of sense of smell 
Drowsiness or loss of coordination
Alcohol related smells on breath 
Alcohol related paraphernalia (Beer bottles, wine bottles, etc