if Mrs. C and her father married, I agree. She would both expect her father to remain single, since he already has for so many years, and if he were to marry, she would expect him to marry someone of rank, or at least of good family, and Mrs. Clay is neither. Plus, as has been quoted througout this thread, Mrs. Clay's notions of rank, according to E, are particularly nice--that is, she would expect Mrs. Clay to refuse Sir W if he proposed because Sir W's family and connections would abhor it, much like Lady Catherine expects Elizabeth to do the same if Mr. Darcy proposes, for the same reasons.