A Lady is Honest.
She abhors the false in word and deed.
Lying is a moral problem as much for a Lady as anyone else. A Lady is also concerned about falsity occurring in the social arena where society might not define the falsehood as a lie. In her own character a Lady is vigilant to have what she says and does be directly representative of the reality. False compliments are unbecoming as much as insults are impolite. A Lady must learn to be kind without resorting to lying. Her behavior must announce only what is true. A gathering she hosts obstensibly as a party must not be a device for subjecting the attendees to a sales pitch of some sort. This is true because everyone who hears or sees a communication from a Lady must be able to depend on the claims made. Actions or beliefs subsequent to a falsehood will produce error and error will release chaos that was unnecessary. Even a unexpected failure must not be covered up but ought to be met with direct admission of the demerit. It should not ever be "I decided that soup was a better choice for our gathering," if you burned the roast. It should be "I must apologize for I burned the roast. We will be having soup instead."
A Lady also becomes an audience that expects to be dealt with truthfully. The realms of good society are valued and it is not unlikely that aspirants to that value will be tempted to bend the truth in order to enjoy those goods. This is one of the small things in which a Lady ought to be adept. Knowing that others might have conveyed a falsehood she should discover what is true and adjust her ear and behavior to correct the lie's damage. This may be anything from not listening to gossip (rife as it is with untruth) to striking a certain person from future guest lists for damage they introduced by playing their inclusion dishonestly. Those who honestly enjoy an honest person's benefits find that the social moment is confidently at peace.