I really hope rey isn't lukes daughter. Starwars has way too man coincidences that it would probably piss me off if "rey, who was abandoned on a planet who happens to find a stormtrooper deserter, who happens to have plans for the rebel base, to then coincidentally find han solos ship and then coincidentally be picked up by han solo to fight kylo who coincidentally is hans son, is also coincidentally lukes daughter." And that is just from this movie.
Starwars has too many coincidences, there is literally a universe out there and there is no way everything should be linked.