I Was Anastasia by Ariel Lawhon

Anastasia Romanov and her family died in a firing squad in 1918 after being imprisoned didn't they?
Anna Anderson is fished out of the water delirious and claiming to be the Grand Duchess Anastasia but she couldn't be could she? The story goes back and forth from the Romanov's cruel treatment after the overthrown government and then to the story of Anna who seems to go between mental hospital to live thanks to the kindness of strangers and friends who support her claim to the Romanov legacy. Anna's description of the treatment of her family is brutal and violent and instead of being relieved to have survived she seems petty and churlish with her friends and caretakers. Shocker ending and one of the best author's notes I have read in some time. Fight the urge to peek at the ending and you will be rewarded.