I wonder if accepting fictional biography/memoirs would make the category far too inclusive. For instance both Great Expectations and David Copperfield would qualify if that were the case. And there are a great many more--any fictional work based on real situations which give the impression of having a semi-auto biographical slant could be a possible choice. If that's what members wish--then of course they can so decide, but in normal literary terminology Biography, Autobiography, and Memoirs are usually considered to be non-fiction.
But of course it's entirely up to yourselves.