HI, thanks for using healthcare magic
Benadry is not known to have an effect on the liver.
The cirrhosis is more likely related to the chronic alcohol use. There are other causes of cirrhosis such as (1)hepatitis
(3)due to conditions such as wilson's disease,
(4)side effect of medication such as amiodarone
, alpha methydopa
These are only some of the other causes of cirrhosis.
The treatment would involve addressing any symptoms that your wife may present with and addressing nutrition.
I hope this helps