Ok, Amanda, we're sure the drawing on everything is super annoying and all. But really we'd love to have Hester and Lester as our little sibs. Not only do they have adorable names, but they are super loving little munchkins.
Sure, Hester and Lester get in trouble too. But it's adorable trouble. It's the kind of innocuous trouble-making that makes adults say, "Oh, those rapscallions" with a twinkle in their eyes. They're not felons in training; they're just kids.
And really, they're children in the true sense of what childhood can be. Their biggest act of rebellion is going on a bath strike: "They placed their hands on Lyle, Lyle Crocodile and swore they would never take another bath until Amanda joined them" (13.16).
So yeah, they make some mistakes, they cause some trouble, but they have love and support to steer them in the right direction.
When Maniac arrives at the Beales, he has pretty much no experience at being a member of a family. His stay with them could have gone pretty badly, right? And we can thank Hester and Lester for the fact that it turns out to be a good experience. The kids are immediately excited by Maniac and make him a part of their lives:
Hester and Lester came screaming down the stairs with a book, Amanda screaming even louder after them, the kids shoving the book and themselves onto Maniac's lap, Amanda finally calming down because they didn't want to crayon the book, they only wanted Maniac to read. (12.19)
Hester and Lester don't give Maniac a choice as to whether or not he wants to be a part of their family: they shower him with love from the very beginning and make it easy for him to do the same back.
So why does he leave them? Maybe as much as Maniac loves being part of the Beale family, he's got some important lessons left to learn on what exactly it means to be a family member.