For those who think Fanny dull, here's a quote from Chapter 12 that I hope will go a little towards proving otherwise:

It was Fanny’s first ball... It had, however, been a very happy one to Fanny through four dances, and she was quite grieved to be losing even a quarter of an hour.

Looks like Tom needs a SUTH for neglecting his cousin! If she had danced the other four, it must have been with Edmund, Mr. Rushworth, Mr. Crawford and Mr. Yates, perhaps in that order.

It's interesting that Fanny is not even considered when the young people all go riding together, but she is included in the dance. Really, things seem to be so arbitrarily decided as far as Fanny goes!