Ms Linda Jackson
Please give advice on How to deal with a daughter-n-law that lies and causes division within the family.

Without knowing more of you situation, the DIL may be getting negative due to a problem she feels is not being addressed. Sometimes we will give the impression without knowing it, a less accepting atmosphere toward people we perceive as outsiders of the family. She is family now and you have to teach her by your actions that you accept the fact and let her know you feel this way.

If you can find out what is eating at her, let her know in a kind way that you will help but wont tolerate intentional division created within the family, then the healing will begin. Some people take this approach as being hostile but that will depend the way you handle the situation. Be up front with her, let her know you accept her as she is and that you wish to be treated the same.

Assuming and knowing someone is telling a lie is all in how you receive your information. You can start with the source of the information, decide on how it was passed down to you and see that mostly, by accident, the information was presented to you in an unreliable manner. We tend to assume it is a lie and hold it against the person we think told it. Get your facts straight first from the horses mouth. "He said, she said" won't work if you believe everything you are told. Good luck to you.

This is no easy problem. The first thing would be to identify that which makes the daughter-in-law to feel it necessary to use lies or to cause dissention in the family. Often it could be a feeling of insecurity or potential threat. This could be serious if she feel that you are possessive over your son or that she does not get the total attention and love from her husband.
The insecurity could also stem from her concern that new as she is she is not yet accepted b the rest of the family and she may be trying devious means to be accepted by he family, especially the husband.

The right way to deal with such a daughter-in-law would be to give her a sense of security, a feeling that she is accepted and loved. Also it is very important that the couple should be given freedom to be on their own without much of intrusions by the rest of the family.

The best remedy for all such social evils is selfless love. The in-laws must accept her for what she is and treat her with love remembering that she is not a stranger or newcomer but one in the family.

All the best. I wish and hope that soon the matter would have a happy solution even if they are not on the lines suggested by me.

There is a lot of background info that is missing here so I will have to generalise for the moment, please add more if you can.

You will have to confront her attempt at lying but it has to be done in a non personal way and only comment on the facts.
She has a problem or issue for whatever reason so get her talking is the name of the game here and she won't if she feels she is being judged or criticised, however immature she may come across as.

In my humble experience the possible causes could include, jealousy, guilt, feelings of inferiority, and even stress etc. These could seem worse the younger she is.

Be patient, upbeat and approachable at all times and it will sort it self out in due course.

Regards