>>23459597(2/2)
The last clue is the electricity specialization.
Electricity is tied to life. The three of that family all use an electric type pokemon (Ampharos, Electric gym mons and Luxray, NENENE). The three of them use that type because it's related to the absence of life of Bonnie and Clemont's mother.
So when Bonnie tries to find a bride for Clemont, it's not just because she wants someone to take care of him. It's because deep down she blames herself for her mother being dead and wants to find someone that can take care of Clemont like their mother was unable to do, and most importantly, to find someone who can take of her and be the mother she never had.