Butterfree is Vivi(Vivillon)'s grandma, and together they work as maids in the same universe as Leafeon and Suicune.

They work for any somewhat wealthy household that will take them. Butterfree (grandma) is quite tired of her role already, but gets jobs easily for her professionalism, and she makes quick friends with their new housefolk. Vivi is a very charming, outwardly sweet young lady who really likes keeping places clean and organized. 

They never stay in  the same household for longer than a year. The reason is that once Vivi gets frustrated enough with her work, how things or people aren't as organized and clean as she wants them to be, she finds impulsive and even sadistic ways to vent her emotions. A few of those times have ended in dead bodies.

Butterfree is horrified when she sees what's happened, but she loves her granddaughter too much to ever turn her in to the police no matter what she's done. So if something happens, she would help Vivi hide evidence. Whenever Butterfree notices beforehand that Vivi is going into "that kind of" mood again though, she'll try to prevent things from turning worse.