Hello Shep, thanks for coming to the forums and certainly appreciate what you have told us as I used alcohol as a way to self medicate when suffering from depression, now I haven't had a drink for well over 2 years.
Being a cupboard drinker or hiding what she needs to drink in certain spots she has decided on, could be anywhere or she could fill up jars, bottles whatever she likes and may hide them in the pantry, behind a book or some obscene hiding spot, somewhere you would never believe she could.
Not all alcoholics are to blame, they need it for many different reasons and it may not have anything to do with you, because any mental illness of any type may just suddenly take over a person for no specific reason, although I'm not a doctor to say, but know from what happened to me.
To just love and support them may benefit some people, otherwise, it can certainly encourage them to keep drinking and not address the problem and the situation to become worse, this all depends on your situation and the response you may receive.
People can be told to stop, cut down or slow down their drinking, but it's only up to them to decide whether or not that's what they want to do, it's their decision, no matter how much you love them.
If a therapist is able to find out why she needs to drink, then the possibility of her stopping is possible, but she needs to accept that she does have a problem and only until then, she has to realise the consequences of what it's doing to the family.
You may have questions you want to ask so please do so.