Where are you seeing that Cal Poly’s tuition is $10k. on the Cal Poly website it says that tuition is about $2k per quarter…3 quarters is $6-7k per year.
https://www.calpoly.edu/financial-aid/types/grants/state-grants/cal-grants
https://afd.calpoly.edu/fees/estimated-fees
Cal Grant A pays for tuition regardless if it’s UC, Cal Poly, or CSU.
Frankly, since you live in Southern Calif and you have a modest income, why would you consider taking on debt for SLO? how much debt would you be taking on for all four years?
Also, there’s travel expenses to also consider.
I saw that you were asking about summer aid for your dd to take two courses…take those at a local CC…just make sure that they’re the right Chem and Physics classes.