There are 2 books in the The Old Maids' Club series. The newest book is Pariah which came out in 2014.

1
Wallflower

Book cover of Wallflower
The choice between adhering to a long-held pact and finally accepting love could prove Lady Tabitha Shelton’s unhinging. She is plump, plain, pleasant . . . and thoroughly unappealing to any of the men of the ton—apart from fortune hunters. A self-appointed wallflower, she has every intention of remaining one.…
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2
Pariah

Book cover of Pariah
After selling his major’s commission in the Dragoons, Lord Roman Sullivan wants nothing more than a calm, sedate life in the country where he’s agreed to act as steward over his father’s estate. Society is no place for a man who can’t sleep without fear of attacking an innocent in…