The Wallflower: Lillian Bowman.
Facing financial ruin, Annabelle is determined to marry a titled nobleman. Instead, she finds herself pursued by Simon Hunt, a wealthy and arrogant self-made businessman who has no interest in marriage—only in making her his mistress. Lisa Kleypas Die Wallflowers 01 04 rar
Here is the content of the first four books included in that set: The Wallflower: Annabelle Peyton. The Wallflower: Lillian Bowman