Hi Granniekanice_1! I am also a 21 year old woman with diagnosed Bipolar and Borderline. After being on Lithium myself, my Doctors have always told me it is not recommended to drink alcohol on this medication, but only because it affects your mood, not because it is dangerous. There are no known interactions between the two, yet it is advisable with Bipolar to avoid any sort of substance/alcohol/drug abuse, as it can make manic and depressive episodes worse. Alcohol can also be a trigger for an episode - it is for myself anyway.
Is she accepting her Bipolar as a problem or is she still in denial?
lithium can cause bac to get really high, and sometimes its hard to tell when someone is drunk when taking lithium , atleast that is my experience, its a salt so it affects the body in hydration , so does alcohol , both dehydrate,