She is characterized as having a good heart, but not enough education and refinement to make her attempts at usefulness acceptable to the other residents of Highbury.
The story continues after the time frame of Emma. The Eltons become parents to a son and the Augusta's sister, Selina, and her family visit. The Sucklings are so vulgar that all of Highbury feels sorry for Mrs Elton and begin to try and understand her. The visit is the beginning of a bit of the acceptance that she has always craved.
This is a nice little story that gives another plausible perspective on the happenings in Emma.