Who is Mrs. Lackersteen from Burmese Days and what is their importance?

Mrs. Lackersteen, like Flory, was born around1890. She is a fairly attractive woman, but has an adolescent body type—Flory considers her "contourless", and Lackersteen apparently finds her only mildly attractive. She is thirty-five years old and displays an amazingly negative racism coupled with an equally distasteful classist view aided by a generous amount of ignorance.