My child and I both have the flu, so I am worried about my other 2 children?

2 things. A whole bunch of hand washing and nose wiping. Still, without med. Isolation those viral particles are now apart of your home. Decrease your concern by consulting your pediatrician. I'm thinking tomorrow.
Already done. It is very difficult to prevent the spread of illness within the family. You were contagious 1-2 days before you knew you wereill.