What is Tris afraid of?
Besides, what are Tris Prior's fears?
Tris originally had 7 fears, but later had 6 which included: To be devoured by crows - symbolic of powerlessness. Drowning in a tank of water - symbolic of weakness and inability to escape. Men reaching for her in her Abnegation room - symbolic, scared of death.
Moreover, how does Tris overcome her fears?
By overcoming her fear, Tris is able to become braver and stronger. She finds her true identity and realizes her ability to be different can't be controlled. With her newly found confidence, she is ready to take on even more challenging obstacles that are to come.
(Major spoiler ahead for non-book readers.) At the end of the Allegiant novel, Tris dies as she disseminates the memory serum to those in the bureau's compound, including David, in an attempt to stop them from further discriminating and abusing "genetically damaged" people.