Please explain the bolded parts

And for her fans, young and old, Dorothy Edwards will remain the creator of a naughty little sister who, whether she is fidgeting or grumbling, refusing to eat her crusts or covering herself in trifle, hiding from fireworks or biting Father Christmas, throwing her sis’s doll out of the window or paying a formal visit on Mrs Cocoa Jones is at all times and unquestionably herself.