Oh another, I hadn't seen her for ages, and then my DM rather unkindly pointed out that all her visits to me coincided with her DC birthdays and one day on a Bank Holiday I went out drinking with some work friends - came home to a message asking if she could come over. Tipsy, I answered yes.
That was the night I realised one of my best friends was an alcoholic.
During the course of a very long night it was so bad I became afraid of her, angry and aggressive and ranting on the phone to her ex. She drank nearly a full litre of vodka and still got up the next day, which made me realise that this wasn't a one off. I stayed up all night because I was afraid she'd die in her sleep. But what was worse was that she'd told crazy batshit lies about me on the phone to her ex and the fact that she could do that and WHAT she said and the tone she used made me realise that she was contemptuous of me deep down and that was a bit heartbreaking.
Even so, when she was sober I tried to sort her out and get her into rehab, as I was sure she would lose her kids, but she denied she had a problem and cut me off
She lost her kids 
but did go on to get dry and regain some custody.
Last time I saw her was years ago in the city and she pulled a face at her friend as if to say "oh I'm sorry, bit of a pain in the arse, but I know that girl, and I'll have to go speak to her" and she was extremely fake and phoney to me and I'd go as far as to say superior.
She has literally nothing to be superior over me about.