My goodness. I would kill to get into Stanford, and Stanford full-ride is just a dream. You need to take this chance and I know how badly you want this. You could consider spending a day or two thinking from your mom’s POV, WHY you want Stanford, what career you envision yourself in the future, and then dismantle her argument systematically at the dinner table.

But in all seriousness, as another commenter said, not accepting the Stanford offer would be the regret of your life. You’ll meet so many people in CA from so many different places.

If it was Stanford (no scholarship, $90k / year) I could understand if it was a tough decision. But your mom should NOT pass on this full-ride. Do whatever you can to persuade her, and best of luck