How can I convince my mom to let me go to public school?

Don't say it's because of the money. Say you're lonely and want to get out and meet new people. Tell her in college you don't want to be the socially awkward kid who doesn't understand the new hypes people are talking about. You can join theater, chorus, debate team, yearbook, all counted towards college. You're ready to face the real world, and you don't want to bottled in the safe haven called "home." Act like its always been your dream to go to public school, how you want to be like them and branch out. I hope this helps you!