Sure that's all cool little callbacks and stuff but what's the actual narrative reason for her to related to kenobi? Like what would the audience gain from learning that kenobi had a secret family
no one knew about? I guess I just don't get why this over her being a skywalker, besides it being kinda cool.
Well first of all it would make an interesting story for the eventual Obi-Wan spin-off.
In terms of this trilogy, it would make sense for Luke to be protective over a descendent of Obi-Wan. Perhaps even adopt her as his own, sending her away when things go bad and not wanting to see another Kenobi die at the hands of his family.
But when Rey comes back to give him his father's lightsaber as Obi-Wan did all these years ago he knows what he must do.
And remember Kylo has been attracted to the dark side probably since birth. This we learn in the conversation Han and Leia were having in this film. So for Luke to have a kid when his father succumbed to the dark side and seeing his sister's son fall to the dark side as well would be quite a leap for the character.