Professor Ivy's assistants
The triplets appeared in Poké Ball Peril. Though they are useful at research assistance, the three women are not particularly good at domestic duties. Their need for someone to handle the cooking and cleaning around the house reminded Brock of his family, which is one reason why he stayed behind as an assistant for Professor Ivy instead of traveling with Ash through the Orange Islands.
They reappeared in a flashback in A Tent Situation.