What exatally is a Mary Sue?

^ That's an interesting question. Most people consider a Mary Sue as either a) a character with no flaws or b) an idealised version of the writer inserted into the story. Or both.

I personally don't consider her a Mary Sue, but I've heard that some people do and I was interested in finding out what people think.

No she is just strong in the force, we just dont know why yet. There is a difference. Plus her flaws could be not trusting people enough, or that she should have embraced her heritage as a Skywalker when Maz told her. Cause lets face it - she most likely 98-100% is Luke's daughter. Daisy said herself that Rey's parent/heritage will be answered by the end of 7 but not explicitly said aka NO WORDS SPOKEN? hint hint.

is close to one (for the fast learning of the force) ,but i hope they fix it in the episode VIII cause i really like her

All of her "mary sue" qualities can be easily explained both by her upbringing and possible family connections to the Skywalkers.

After seeing TLJ I can firmly choose no on this. We finally saw some of her flaws in the TLJ and how seduced she was by the darkness.

The easiness of her being seduced by darkness, her lack of identity and her clinging to the idea of her lost family are all strong enough flaws to prevent her from being a Mary Sue. That title gets thrown away far too easily and attached to any character (especially female protagonists) which people just dislike.