Answer:
Lily meant to imply that she almost succeeded in making Percy Gryce agree to marry her.
Step-by-step explanation:
Edith Wharton's The House of Mirth revolves around the life of Lily Bart who is trying hard to attract a wealthy man for her husband while she has her beauty. But as the story unravels, she met some unfortunate fate where she was despised, wrongly accused and even let go from her job, while at the same time missing out on a huge inheritance money from her rich aunt.
In the initial years before the death of her aunt and the numerous accusations, Lily was adamant in getting herself a rich husband. When she says that she almost "landed" (chapter 3) the wealthy but boring young bachelor Percy Gryce, she is implying that she almost succeeded in getting him as her husband. "Landed" is a word used to signify a successful possession.