Let's use the same lame logic for Rey suddenly being a trained Jedi with other movies
Neo has one lesson with Morpheus, learns Kung Fu and defeats the Agents in the final showdown with no other training.
Beatrix acquires the Hattori Honzo sword with zero training from Pai Mei and defeats Bill with the five finger death punch.
Ender Wiggin jumps behind the controls with zero training and stops the Formic invasion.
If any of these movies had had this plot everyone would be up in arms and saying it's the dumbest story line ever.
But since Rey has never had any type of Jedi training and almost takes down a TRAINED Jedi (Kylo Ren) with years of training it's suddenly okay but fanboys want to use the sexist card for anyone who complains about.
I don't care if Rey was male, female, a wookie or a gungan it's absolutely stupid and ridiculous to use logic to dictate that someone who has zero knowledge of the force and zero training with a light saber can suddenly pick one up and beat down a better trained warrior.