Eureka is Citron's younger sister. She met Ash in Niare City and she and her brother were his very first battle opponents in the Kalos region, a battle he won't forget soon.
Bonnie is a girl of strong character, who's always searching for a future wife for her brother. Since she's not a Pokémon Trainer yet, but she gets
Clemont to "keep" Pokémon for her. She was confirmed to be in the XY anime in
Smash #153. Eureka's Japanese name origin is from the eureka lemon.