Deal Before the Altar
Publisher: Harlequin Enterprises, Limited
Published: 2014
Language: eng
Number of pages: 192
ISBN-13: 9780373132867
Subjects: Fiction, romance, general
First sentence: GEORGINA ENTERED THE sleek luxury of the office and knew she was being watched. Her every step scrutinised by a man who was revered and feared by businessmen and women alike.
Description: She proposes to him,
they get married .... so he will inherit his company 
and her sister can marry his brother

Note:
See if you can figure out how old their siblings are.
Just curious