Have you two tried scrunching after you brush? I brush too, but really only for detangling and clumping. Brushing does stretch out my curls too so I have to scrunch them after I brush them.
As for your roots, you could try butterfly clips to add lift.
Give it a try when you don't have anywhere to go for the day, that way if it doesn't work you can re-wet your hair and style it the way you normally do. Good luck!