But it was never mentioned in the books that she wrote.
Bipolar, but is finally on the right drug regimen and has her life together again--good for you, Ms.
We will never know the answer to your question unless one of them has an unpublished true story to be released to public at some determined time in future.
Debbie was also rumored to have been involved with Shelley Winters and Debbie, Shelley and Agnes made the bizarre 'What's the matter with Helen' movie in which is was clear that Shelly's character was in love with Debbie's.
That was a novel, by the way.
Or are you under 30? As for proving someone is gay - there are no tapes or photos proving John Travolta is gay but no one with any sense doubts that he is.