Rebattle the elite4.
every time you beat the Elite four, red will appear at the top of Mt. Silver again
yup you can
You'd have to use cheats.
I'm sorry, my last answer was wrong, you can rematch them, but you first have to get their number, and some of them will only rematch you on certain days.
Wednesday from 10 to 19:59
on any day go to diglet cave
You have to receive their number in the Pokegear and call the at specific times
You can call certain ones depending on what day it is.
You go up to her click b,b, a, and then splooge in her face :) helpful
you battle trainers again by adding them onto your pokegear and then soon they will want a rematch
Call her on monday afternoons, and she will ask for a rematch at the Saffron City fighting dojo.
on the peak of mt silver