I think over the years we have built up our understanding of each member of the IF by putting together all the accounts available and sifting through them, rejecting the unreliable and flimsy, and building up on those we consider trustworthy. Perhaps Paul Gilbert's forthcoming book 'Born in the Purple' will finally provide a true picture ~ at least as far as OTMA are concerned. For me, the accounts below have proved to be pretty good, even given the passage of time :
At the Court of the Last Tsar (Mossolov, 1935)
Thirteen Years at the Russian Court (Gilliard, 1924)
Last Days at Tsarskoe Selo (Benckendorff, 1927)
The Real Romanovs (Botkin, 1932)
I believe all are available to read on the main AP site.