For me being the youngest, there was never ever anything that was an issue to cause rivalry between me and my sisters.
I never had a rivalry with Madonna. You don't knock another sister, ever. There's room for everybody on this planet; you don't have to be like anyone else.
My sister and I never engaged in sibling rivalry. Our parents weren't that crazy about either one of us.
Rivalry doesn't help anybody.
Sister is probably the most competitive relationship within the family, but once the sisters are grown, it becomes the strongest relationship.