Leave Avril alone tbh, it's obvious that she doesn't hate Britney and likes some of her music, I mean even in these videos she sings like 4 different Britney songs.
She might have said some stuff in the beginning of her career, but let's not forget she was marketed as anti-Britney and had to step her foot at the door so I'm sure some of the controversy was planned by her label and then fueled by the press.