Hello, I am Rafael. Thanks for asking your question - I'm here to support you. (Information posted here is not private or confidential but public).
I am very sorry to know about this serious and concerning situation.
First I have to say that the scenario you depict seems to be truly overwhelming for anybody in your shoes.
I say this because when a mental disorder like compulsive lying syndrome or pathological Lying syndrome occur, tough life challenges arise affecting the person suffering of these disorders and those around them.
it is a tough situation because it leads to a very complex reality, where web of lies get more and more complicated, and if your daughter does not only lie out of compulsion and habit, but with the intention of manipulating and when aware of how painful and hurting it could get, then her situation would become even much more serious.
Most times people presenting these syndromes do also have other mental health disorders, from self-image issues, to temper problems, personality disorders and addictions, this is why psychotherapeutic treatment becomes so essential in order to provide some concrete chances for rehabilitation.
She is not a teenager anymore but an adult, and has a little daughter, who requires of adequate caring, protection, love and support, which seem to be deeply undermined by her serious mental health disorders.
Could you please tell me more about her behaviors? You said she has been very hurtful. Could you please comment a little more about that?
She is saying things like her child is very ill.she tells us things about other people which are not true.she turns people against each other.I have to go to a appointment. Is there ever good results with help? Medication?
Medication cannot help with pathological lying S, but it could help with other disorders and symptoms associates to it. it is through psychological/behavioral treatment that people could work on their rehabilitation process and make progress with time. this is a chronic mental illness and requires psychotherapy for sure and a healthy support system for the person to have chances of rehabilitation.
The most concerning point here is that she has been lying in order to manipulate and hurt people, which shows the antisocial nature of this personality disorder, which must be addressed as such. Your role as family is to set healthy and clear limits and boundaries, offering emotional support and guidance, eradicating any form of possible codependency and not tolerating any form of neglectful or abusive behavior.
She should be accountable for her choices and actions, otherwise any help she may receive from people who care, could become the very fuel for her disorders, leading to further pain and dysfunction, and in this case there is a child involve, who would be a helpless victim in this situation, and that's very concerning.
She needs psychotherapy to work on the personal issues related to this disorder, otherwise she would not make improvements but tend to get worse. Please look for counseling support for you and your family to know how to effectively cope with these serious challenges and support her in healthy ways, setting necessary limits and boundaries. it's very frustrating but as long as she does not choose to acknowledge she has big problems and requires treatment, taking responsibility for her life, there is not much anybody could do for her.