File both civil and criminal defamation against her by your father, mother and sister.
File speedy trial in High Court for you. Anyone from your family like father, mother or any relative can plead in High Court for you for speedy trial. Please note that it is mandatory else case will be dragged life long. Speedy Trial petition and other clues are available on my following links.
Please read each posts carefully on my links bellow -
https://www.lawyersclubindia.com/forum/Fight-against-misuse-of-498a-ipc--103100.asp#.U6gslUCm9dg
https://www.lawyersclubindia.com/forum/Best-way-to-fight-against-false-498a-103111.asp#.U6gsRkCm9dg
https://www.lawyersclubindia.com/forum/details.asp?mod_id=104564&offset=1