While she sees Lizzie as being an evil monster who wants to destroy her mother's life because said mother is too dim to understand how children think, we see a small child who wants what other people have because she wants to be able to relate to them. This need of Elly's to either not understand this simple desire to fit in and not be some creepy isolate or to interpret as a means by which evil strangers dictate to her because evil strangers are evil comes into play a lot in the Middle Years. Always and ever, Lizzie feels as if she's on the outside looking in because everyone else gots somethin'an'she don't and always and ever, Elly makes that stupid looking palms out pleading gesture as she bleats about the need to make children wear uniforms so she doesn't have to be forced to buy clothing for the useless purpose of making a child fit in with the herd.
What makes this all so very silly is that the real reason she complains about how expensive it is to clothe children to please other children is that it denies her the chance to blow high dough on duds that set her up with the Quality Women. Simply put, kids should be dressed all alike in order that Elly can do the same damn thing she condemns in her children. Not that she admits this because she's not really any more honest than she is loving, fair, firm or kind.