Oil changing
If she uses regular oil (https://www.yourmechanic.com/article/can-you-switch-between-regular-and-synthetic-motor-oil), I'd change it every 4,000 or 5,000 if I were her. You can change your oil (https://www.yourmechanic.com/article/when-should-i-change-my-oil) every 6-8,000 with synthetic, but I wouldn't change regular every 6,000. If you do a lot of...