it is summer and all she says is that "every few years all the champions battle eachother" so can i battle her or must i wait until spring. Also can i fight the champions
Well, When it was summer she wouldn't battle me every day, but she did in spring, so I'm guessing that Serebii is just jacked up about their info again, and you Can Only battle in spring.
Solution
Wait till Spring!
This is an educated guess but in summer i think that she battles on weekends
She always battles me, so i think you must not have completed a certain requirement, and btw, she battles me everyday, in every season, but i battle her after the elite four so..... maybe that is why?