The whole story is not designed to make all that much sense, good luck for the authors of the sequels to tie everything up. Some basic things are just left hanging in the air (if there is a new Republic now, how the First Order and the Resistance came to be etc). First I thought that Rey was a Jedi student as well and after Kylo’s turn to the dark side she was placed on Jakuu with her memories suppressed to hide and protect her, and the Falcon was there as sort of an escape option in case she gets in trouble. But no, it’s all just a coincidence.
The Force works in contrived ways.
Do you plan on watching the movie with an open mind? I’m getting an angry old man, yelling at sky vibe here.