My wife (soon to be ex) is an unemployed drunk who is used to getting her way through lawyers (thanks to her parents) and is expecting to get full custody of our 2 yr old daughter as we have split and are seeking a divorce. She already has full custody of her son from a previous relationship but the little girl is mine.
The problem I have is that even though we have mutually agreed that I see my daughter every other weekend, I still see her hungover and stinking of alcohol each morning I see her. I don't want her crashed out on the couch with a hangover (still drunk) while my 2 year old runs around her house getting into painkillers and scissors etc...
How can I prove that she is unfit to care for my daughter fulltime if I don't have much evidence except word of mouth and my own concerns. This really upsets me as I can't see how I can get my baby girl out of this "arrangement" and have her here with me where she will be cared for properly with no hangovers and dangers of getting hurt because Mommy is too hungover to get up and care for her properly.
Any advice would greatly be appreciated. Thank you.

If you don't have evidence - legally obtained - you won't have much ground to stand on.

Go to court, request full custody, express your concerns and hope for the best. Make sure you have a good lawyer.